diff --git a/base/applications/cmdutils/taskkill/lang/de-DE.rc b/base/applications/cmdutils/taskkill/lang/de-DE.rc
index 54a408fcc8a..01da0f287f9 100644
--- a/base/applications/cmdutils/taskkill/lang/de-DE.rc
+++ b/base/applications/cmdutils/taskkill/lang/de-DE.rc
@@ -2,7 +2,7 @@ LANGUAGE LANG_GERMAN, SUBLANG_NEUTRAL
 
 STRINGTABLE
 {
-    STRING_USAGE, "Usage: taskkill [/?] [/f] [/im Prozess Name | /pid Prozess ID]\n"
+    STRING_USAGE, "Usage: taskkill [/?] [/f] [/im Prozess Name | /pid Prozess ID] [/t]\n"
     STRING_INVALID_OPTION, "Fehler: Unbekannte oder ungülige Kommandozeilenoption angegeben.\n"
     STRING_INVALID_PARAM, "Fehler: Ungültiger Kommandozeilenparameter angegeben.\n"
     STRING_MISSING_OPTION, "Fehler: Eine der Optionen /im oder /pid muss angegeben werden.\n"
@@ -16,6 +16,9 @@ STRINGTABLE
     STRING_ENUM_FAILED, "Fehler: Prozessliste kann nicht aufgebaut werden.\n"
     STRING_TERMINATE_FAILED, "Fehler: Prozess ""%1"" kann nicht beendet werden.\n"
     STRING_SELF_TERMINATION, "Fehler: Der Prozess kann sich nicht selbst beenden.\n"
+    STRING_CLOSE_CHILD, "Close message sent to top-level windows of process with PID %1!u!, child of PID %2!u!.\n"
+    STRING_TERM_CHILD, "Process with PID %1!u! was forcibly terminated, child of PID %2!u!.\n"
+    STRING_TERM_CHILD_FAILED, "Error: Unable to terminate process with PID %1!u!, child of PID %2!u!.\n"
     STRING_PARAM_TOO_MUCH, "Error: Invalid syntax. '%1' option is not allowed more than '%2!d!' time(s).\n"
     STRING_INVALID_SYNTAX, "Error: Invalid syntax.\n"
 }
diff --git a/base/applications/cmdutils/taskkill/lang/en-US.rc b/base/applications/cmdutils/taskkill/lang/en-US.rc
index e34b34bad25..b1151dcacb2 100644
--- a/base/applications/cmdutils/taskkill/lang/en-US.rc
+++ b/base/applications/cmdutils/taskkill/lang/en-US.rc
@@ -2,7 +2,7 @@ LANGUAGE LANG_ENGLISH, SUBLANG_DEFAULT
 
 STRINGTABLE
 {
-    STRING_USAGE, "Usage: taskkill [/?] [/f] [/im ProcessName | /pid ProcessID]\n"
+    STRING_USAGE, "Usage: taskkill [/?] [/f] [/im ProcessName | /pid ProcessID] [/t]\n"
     STRING_INVALID_OPTION, "Error: Unknown or invalid command line option specified.\n"
     STRING_INVALID_PARAM, "Error: Invalid command line parameter specified.\n"
     STRING_MISSING_OPTION, "Error: One of options /im or /pid must be specified.\n"
@@ -16,6 +16,9 @@ STRINGTABLE
     STRING_ENUM_FAILED, "Error: Unable to enumerate the process list.\n"
     STRING_TERMINATE_FAILED, "Error: Unable to terminate process ""%1"".\n"
     STRING_SELF_TERMINATION, "Error: Process self-termination is not permitted.\n"
+    STRING_CLOSE_CHILD, "Close message sent to top-level windows of process with PID %1!u!, child of PID %2!u!.\n"
+    STRING_TERM_CHILD, "Process with PID %1!u! was forcibly terminated, child of PID %2!u!.\n"
+    STRING_TERM_CHILD_FAILED, "Error: Unable to terminate process with PID %1!u!, child of PID %2!u!.\n"
     STRING_PARAM_TOO_MUCH, "Error: Invalid syntax. '%1' option is not allowed more than '%2!d!' time(s).\n"
     STRING_INVALID_SYNTAX, "Error: Invalid syntax.\n"
 }
diff --git a/base/applications/cmdutils/taskkill/lang/it-IT.rc b/base/applications/cmdutils/taskkill/lang/it-IT.rc
index 0cb456bd91e..3c9ebf0f2ce 100644
--- a/base/applications/cmdutils/taskkill/lang/it-IT.rc
+++ b/base/applications/cmdutils/taskkill/lang/it-IT.rc
@@ -9,7 +9,7 @@ LANGUAGE LANG_ITALIAN, SUBLANG_NEUTRAL
 
 STRINGTABLE
 {
-    STRING_USAGE, "Uso: taskkill [/?] [/f] [/im NomeProcesso | /pid IDProcesso]\n"
+    STRING_USAGE, "Uso: taskkill [/?] [/f] [/im NomeProcesso | /pid IDProcesso] [/t]\n"
     STRING_INVALID_OPTION, "Errore: L'opzione specificata è invalida o sconosciuta.\n"
     STRING_INVALID_PARAM, "Errore: Il parametro di comando a riga è invalido.\n"
     STRING_MISSING_OPTION, "Errore: Specifica una delle opzioni /im oppure /pid.\n"
@@ -23,6 +23,9 @@ STRINGTABLE
     STRING_ENUM_FAILED, "Errore: Impossibile enumerare la lista dei processi.\n"
     STRING_TERMINATE_FAILED, "Errore: Impossibile terminare il processo ""%1"".\n"
     STRING_SELF_TERMINATION, "Errore: L'auto-terminazione non è consentita.\n"
+    STRING_CLOSE_CHILD, "Close message sent to top-level windows of process with PID %1!u!, child of PID %2!u!.\n"
+    STRING_TERM_CHILD, "Process with PID %1!u! was forcibly terminated, child of PID %2!u!.\n"
+    STRING_TERM_CHILD_FAILED, "Error: Unable to terminate process with PID %1!u!, child of PID %2!u!.\n"
     STRING_PARAM_TOO_MUCH, "Error: Invalid syntax. '%1' option is not allowed more than '%2!d!' time(s).\n"
     STRING_INVALID_SYNTAX, "Error: Invalid syntax.\n"
 }
diff --git a/base/applications/cmdutils/taskkill/lang/pl-PL.rc b/base/applications/cmdutils/taskkill/lang/pl-PL.rc
index 5dd0f3ed463..9731945e3e4 100644
--- a/base/applications/cmdutils/taskkill/lang/pl-PL.rc
+++ b/base/applications/cmdutils/taskkill/lang/pl-PL.rc
@@ -9,7 +9,7 @@ LANGUAGE LANG_POLISH, SUBLANG_DEFAULT
 
 STRINGTABLE
 {
-    STRING_USAGE, "Sposób użycia: taskkill [/?] [/f] [/im nazwa_procesu | /pid id_procesu]\n"
+    STRING_USAGE, "Sposób użycia: taskkill [/?] [/f] [/im nazwa_procesu | /pid id_procesu] [/t]\n"
     STRING_INVALID_OPTION, "Błąd: Określono nieznaną lub nieprawidłową opcję.\n"
     STRING_INVALID_PARAM, "Błąd: Nieprawidłowy parametr.\n"
     STRING_MISSING_OPTION, "Błąd: Nie określono opcji /im ani /pid.\n"
@@ -23,6 +23,9 @@ STRINGTABLE
     STRING_ENUM_FAILED, "Błąd: Nie można wyliczyć listy procesów.\n"
     STRING_TERMINATE_FAILED, "Błąd: Nie można zakończyć procesu ""%1"".\n"
     STRING_SELF_TERMINATION, "Błąd: Proces nie może zakończyć sam siebie.\n"
+    STRING_CLOSE_CHILD, "Close message sent to top-level windows of process with PID %1!u!, child of PID %2!u!.\n"
+    STRING_TERM_CHILD, "Process with PID %1!u! was forcibly terminated, child of PID %2!u!.\n"
+    STRING_TERM_CHILD_FAILED, "Error: Unable to terminate process with PID %1!u!, child of PID %2!u!.\n"
     STRING_PARAM_TOO_MUCH, "Błąd: Nieprawidłowa składnia. Opcja '%1' nie jest dozwolona więcej niż '%2!d!' razy.\n"
     STRING_INVALID_SYNTAX, "Błąd: Nieprawidłowa składnia.\n"
 }
diff --git a/base/applications/cmdutils/taskkill/lang/ro-RO.rc b/base/applications/cmdutils/taskkill/lang/ro-RO.rc
index 476201fb5e1..585d025fa09 100644
--- a/base/applications/cmdutils/taskkill/lang/ro-RO.rc
+++ b/base/applications/cmdutils/taskkill/lang/ro-RO.rc
@@ -10,7 +10,7 @@ LANGUAGE LANG_ROMANIAN, SUBLANG_NEUTRAL
 
 STRINGTABLE
 {
-    STRING_USAGE, "Utilizare: taskkill [/?] [/f] [/im NumeProces | /pid IdProces]\n"
+    STRING_USAGE, "Utilizare: taskkill [/?] [/f] [/im NumeProces | /pid IdProces] [/t]\n"
     STRING_INVALID_OPTION, "Eroare: Opțiune specificată nevalidă sau necunoscută.\n"
     STRING_INVALID_PARAM, "Eroare: Parametrul de comandă specificat este nevalid.\n"
     STRING_MISSING_OPTION, "Eroare: Trebuie specificată una dintre opțiunile /im sau /pid.\n"
@@ -24,6 +24,9 @@ STRINGTABLE
     STRING_ENUM_FAILED, "Eroare: Nu se poate enumera lista de procese.\n"
     STRING_TERMINATE_FAILED, "Eroare: Procesul «%1» nu poate fi oprit.\n"
     STRING_SELF_TERMINATION, "Eroare: Auto-terminarea nu este permisă.\n"
+    STRING_CLOSE_CHILD, "Close message sent to top-level windows of process with PID %1!u!, child of PID %2!u!.\n"
+    STRING_TERM_CHILD, "Process with PID %1!u! was forcibly terminated, child of PID %2!u!.\n"
+    STRING_TERM_CHILD_FAILED, "Error: Unable to terminate process with PID %1!u!, child of PID %2!u!.\n"
     STRING_PARAM_TOO_MUCH, "Eroare: Sintaxă nevalidă. Opțiunea '%1' nu este permisă mai mult de '%2!d!' dată(dăți).\n"
     STRING_INVALID_SYNTAX, "Eroare: Sintaxă nevalidă.\n"
 }
diff --git a/base/applications/cmdutils/taskkill/lang/ru-RU.rc b/base/applications/cmdutils/taskkill/lang/ru-RU.rc
index 69ddc4bc113..730475871b0 100644
--- a/base/applications/cmdutils/taskkill/lang/ru-RU.rc
+++ b/base/applications/cmdutils/taskkill/lang/ru-RU.rc
@@ -4,7 +4,7 @@ LANGUAGE LANG_RUSSIAN, SUBLANG_DEFAULT
 
 STRINGTABLE
 {
-    STRING_USAGE, "Использование: TASKKILL [/F] [/IM <образ> | /PID <процесс>]\n"
+    STRING_USAGE, "Использование: TASKKILL [/F] [/IM <образ> | /PID <процесс>] [/t]\n"
     STRING_INVALID_OPTION, "Ошибка: Указаны неверные параметры командной строки.\n"
     STRING_INVALID_PARAM, "Ошибка: Указаны неверные параметры командной строки.\n"
     STRING_MISSING_OPTION, "Ошибка: Должен быть указан параметр /im или /pid.\n"
@@ -18,6 +18,9 @@ STRINGTABLE
     STRING_ENUM_FAILED, "Ошибка: Не удается получить список процессов.\n"
     STRING_TERMINATE_FAILED, "Ошибка: Не удается завершить процесс ""%1"".\n"
     STRING_SELF_TERMINATION, "Ошибка: Процесс не может завершить сам себя.\n"
+    STRING_CLOSE_CHILD, "Close message sent to top-level windows of process with PID %1!u!, child of PID %2!u!.\n"
+    STRING_TERM_CHILD, "Process with PID %1!u! was forcibly terminated, child of PID %2!u!.\n"
+    STRING_TERM_CHILD_FAILED, "Error: Unable to terminate process with PID %1!u!, child of PID %2!u!.\n"
     STRING_PARAM_TOO_MUCH, "Ошибка: Неверный синтаксис. Нельзя использовать опцию '%1' больше '%2!d!' раз(а).\n"
     STRING_INVALID_SYNTAX, "Ошибка: Неверный синтаксис.\n"
 }
diff --git a/base/applications/cmdutils/taskkill/lang/sq-AL.rc b/base/applications/cmdutils/taskkill/lang/sq-AL.rc
index 85878177488..d4300272d66 100644
--- a/base/applications/cmdutils/taskkill/lang/sq-AL.rc
+++ b/base/applications/cmdutils/taskkill/lang/sq-AL.rc
@@ -6,7 +6,7 @@ LANGUAGE LANG_ALBANIAN, SUBLANG_NEUTRAL
 
 STRINGTABLE
 {
-    STRING_USAGE, "Usage: taskkill [/?] [/f] [/im ProcessName | /pid ProcessID]\n"
+    STRING_USAGE, "Usage: taskkill [/?] [/f] [/im ProcessName | /pid ProcessID] [/t]\n"
     STRING_INVALID_OPTION, "Gabim: Panjohur ose i pavlefshëm opsioni linjes komandes i specifikuar.\n"
     STRING_INVALID_PARAM, "Gabim: Pavlefshëm parametri i specifikuar ne linjen e komandes.\n"
     STRING_MISSING_OPTION, "Gabim: Njera nga opsionet /im ose /pid duhet te specifikohet.\n"
@@ -20,6 +20,9 @@ STRINGTABLE
     STRING_ENUM_FAILED, "Gabim: Në pamundësi për të numëruar listën proceseve.\n"
     STRING_TERMINATE_FAILED, "Gabim: Pamundur mbyllja e proceseve ""%1"".\n"
     STRING_SELF_TERMINATION, "Gabim: Procesi vetë-përfundimi nuk është i lejuar.\n"
+    STRING_CLOSE_CHILD, "Close message sent to top-level windows of process with PID %1!u!, child of PID %2!u!.\n"
+    STRING_TERM_CHILD, "Process with PID %1!u! was forcibly terminated, child of PID %2!u!.\n"
+    STRING_TERM_CHILD_FAILED, "Error: Unable to terminate process with PID %1!u!, child of PID %2!u!.\n"
     STRING_PARAM_TOO_MUCH, "Error: Invalid syntax. '%1' option is not allowed more than '%2!d!' time(s).\n"
     STRING_INVALID_SYNTAX, "Error: Invalid syntax.\n"
 }
diff --git a/base/applications/cmdutils/taskkill/lang/tr-TR.rc b/base/applications/cmdutils/taskkill/lang/tr-TR.rc
index d3f28161a2f..c990b148429 100644
--- a/base/applications/cmdutils/taskkill/lang/tr-TR.rc
+++ b/base/applications/cmdutils/taskkill/lang/tr-TR.rc
@@ -4,7 +4,7 @@ LANGUAGE LANG_TURKISH, SUBLANG_NEUTRAL
 
 STRINGTABLE
 {
-    STRING_USAGE, "Kullanım: taskkill [/?] [/f] [/im işlem adı | /pid işlem kimliği]\n"
+    STRING_USAGE, "Kullanım: taskkill [/?] [/f] [/im işlem adı | /pid işlem kimliği] [/t]\n"
     STRING_INVALID_OPTION, "Hata: Bilinmeyen veya geçersiz komut satırı seçeneği belirtildi.\n"
     STRING_INVALID_PARAM, "Hata: Geçersiz komut satırı değişkeni belirtildi.\n"
     STRING_MISSING_OPTION, "Hata: /im ve /pid seçeneklerinden biri belirtilmeli.\n"
@@ -18,6 +18,9 @@ STRINGTABLE
     STRING_ENUM_FAILED, "Hata: İşlem numaralandırılamıyor.\n"
     STRING_TERMINATE_FAILED, "Hata: ""%1"" işlemi sonlandırılamıyor.\n"
     STRING_SELF_TERMINATION, "Hata: İşlemi kendi kendine sonlandırmaya izin verilmedi.\n"
+    STRING_CLOSE_CHILD, "Close message sent to top-level windows of process with PID %1!u!, child of PID %2!u!.\n"
+    STRING_TERM_CHILD, "Process with PID %1!u! was forcibly terminated, child of PID %2!u!.\n"
+    STRING_TERM_CHILD_FAILED, "Error: Unable to terminate process with PID %1!u!, child of PID %2!u!.\n"
     STRING_PARAM_TOO_MUCH, "Hata: Geçersiz sözdizimi. '%1' seçeneğine '%2!d!'den fazla kez izin verilmiyor..\n"
     STRING_INVALID_SYNTAX, "Hata: Geçersiz sözdizimi.\n"
 }
diff --git a/base/applications/cmdutils/taskkill/lang/zh-CN.rc b/base/applications/cmdutils/taskkill/lang/zh-CN.rc
index 008e3f7005f..6ebea33f39f 100644
--- a/base/applications/cmdutils/taskkill/lang/zh-CN.rc
+++ b/base/applications/cmdutils/taskkill/lang/zh-CN.rc
@@ -7,7 +7,7 @@ LANGUAGE LANG_CHINESE, SUBLANG_CHINESE_SIMPLIFIED
 
 STRINGTABLE
 {
-    STRING_USAGE, "用法：taskkill [/?] [/f] [/im 进程名称 | /pid 进程 ID]\n"
+    STRING_USAGE, "用法：taskkill [/?] [/f] [/im 进程名称 | /pid 进程 ID] [/t]\n"
     STRING_INVALID_OPTION, "错误：指定了未知或无效的命令行选项。\n"
     STRING_INVALID_PARAM, "错误：指定了无效的命令行参数。\n"
     STRING_MISSING_OPTION, "错误：必须指定选项 /im 或 /pid。\n"
@@ -21,6 +21,9 @@ STRINGTABLE
     STRING_ENUM_FAILED, "错误：无法枚举进程列表。\n"
     STRING_TERMINATE_FAILED, "错误：无法终止进程“%1”。\n"
     STRING_SELF_TERMINATION, "错误：不允许终止自身。\n"
+    STRING_CLOSE_CHILD, "Close message sent to top-level windows of process with PID %1!u!, child of PID %2!u!.\n"
+    STRING_TERM_CHILD, "Process with PID %1!u! was forcibly terminated, child of PID %2!u!.\n"
+    STRING_TERM_CHILD_FAILED, "Error: Unable to terminate process with PID %1!u!, child of PID %2!u!.\n"
     STRING_PARAM_TOO_MUCH, "错误：无效语法。选项“%1”不允许超过“%2!d!”次。\n"
     STRING_INVALID_SYNTAX, "错误：无效语法。\n"
 }
diff --git a/base/applications/cmdutils/taskkill/lang/zh-TW.rc b/base/applications/cmdutils/taskkill/lang/zh-TW.rc
index 9f2b3637ceb..a6a746dcb7d 100644
--- a/base/applications/cmdutils/taskkill/lang/zh-TW.rc
+++ b/base/applications/cmdutils/taskkill/lang/zh-TW.rc
@@ -11,7 +11,7 @@ LANGUAGE LANG_CHINESE, SUBLANG_CHINESE_TRADITIONAL
 
 STRINGTABLE
 {
-    STRING_USAGE, "用法: taskkill [/?] [/f] [/im 處理程序名稱 | /pid PID]\n"
+    STRING_USAGE, "用法: taskkill [/?] [/f] [/im 處理程序名稱 | /pid PID] [/t]\n"
     STRING_INVALID_OPTION, "錯誤: 指定了不明或不正確的命令列選項。\n"
     STRING_INVALID_PARAM, "錯誤: 指定了不正確的命令列參數。\n"
     STRING_MISSING_OPTION, "錯誤: 必須指定選項 /im 或 /pid 的其中之一。\n"
@@ -25,6 +25,9 @@ STRINGTABLE
     STRING_ENUM_FAILED, "錯誤: 無法列舉處理程序清單。\n"
     STRING_TERMINATE_FAILED, "錯誤: 無法終止處理程序 '%1'。\n"
     STRING_SELF_TERMINATION, "錯誤: 處理程序不允許自我終止。\n"
+    STRING_CLOSE_CHILD, "Close message sent to top-level windows of process with PID %1!u!, child of PID %2!u!.\n"
+    STRING_TERM_CHILD, "Process with PID %1!u! was forcibly terminated, child of PID %2!u!.\n"
+    STRING_TERM_CHILD_FAILED, "Error: Unable to terminate process with PID %1!u!, child of PID %2!u!.\n"
     STRING_PARAM_TOO_MUCH, "錯誤: 無效的語法。'%1' 選項不允許超過 '%2!d!' 次。\n"
     STRING_INVALID_SYNTAX, "錯誤: 無效的語法。\n"
 }
diff --git a/base/applications/cmdutils/taskkill/taskkill.c b/base/applications/cmdutils/taskkill/taskkill.c
index 75706a66491..f0f301acfa9 100644
--- a/base/applications/cmdutils/taskkill/taskkill.c
+++ b/base/applications/cmdutils/taskkill/taskkill.c
@@ -23,6 +23,7 @@
 #include <stdlib.h>
 #include <windows.h>
 #include <psapi.h>
+#include <tlhelp32.h>
 #include <wine/debug.h>
 #include <wine/unicode.h>
 
@@ -31,6 +32,7 @@
 WINE_DEFAULT_DEBUG_CHANNEL(taskkill);
 
 static BOOL force_termination = FALSE;
+static BOOL kill_child_processes = FALSE;
 
 static WCHAR **task_list;
 static unsigned int task_count;
@@ -230,11 +232,74 @@ static BOOL get_process_name_from_pid(DWORD pid, WCHAR *buf, DWORD chars)
  * A PID of zero causes taskkill to warn about the inability to terminate
  * system processes. */
 
-#ifndef __REACTOS__
+
+static BOOL get_pid_creation_time(DWORD pid, FILETIME *time)
+{
+    HANDLE process = INVALID_HANDLE_VALUE;
+    FILETIME t1 = { 0 }, t2 = { 0 }, t3 = { 0 };
+
+    process = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, pid);
+    if (!process)
+    {
+        return FALSE;
+    }
+
+    if (!GetProcessTimes(process, time, &t1, &t2, &t3))
+    {
+        CloseHandle(process);
+        return FALSE;
+    }
+
+    CloseHandle(process);
+    return TRUE;
+}
+
+static void send_close_messages_tree(DWORD ppid)
+{
+    FILETIME parent_creation_time = { 0 };
+    HANDLE h = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
+    PROCESSENTRY32W pe = { 0 };
+    pe.dwSize = sizeof(PROCESSENTRY32W);
+
+    if (!get_pid_creation_time(ppid, &parent_creation_time) || !h)
+    {
+        CloseHandle(h);
+        return;
+    }
+
+    if (Process32FirstW(h, &pe))
+    {
+        do
+        {
+            FILETIME child_creation_time = { 0 };
+            struct pid_close_info info = { pe.th32ProcessID };
+
+            if (!get_pid_creation_time(pe.th32ProcessID, &child_creation_time))
+            {
+                continue;
+            }
+
+            // Compare creation time to avoid reuse PID, thanks to @ThFabba
+            if (pe.th32ParentProcessID == ppid &&
+                CompareFileTime(&parent_creation_time, &child_creation_time) < 0)
+            {
+                // Use recursion to browse all child processes
+                send_close_messages_tree(pe.th32ProcessID);
+                EnumWindows(pid_enum_proc, (LPARAM)&info);
+                if (info.found)
+                {
+                    taskkill_message_printfW(STRING_CLOSE_CHILD, pe.th32ProcessID, ppid);
+                }
+            }
+        } while (Process32NextW(h, &pe));
+    }
+
+    CloseHandle(h);
+}
 
 static int send_close_messages(void)
 {
-    DWORD *pid_list, pid_list_size;
+    DWORD *pid_list, pid_list_size, *pkill_list;
     DWORD self_pid = GetCurrentProcessId();
     unsigned int i;
     int status_code = 0;
@@ -246,10 +311,17 @@ static int send_close_messages(void)
         return 1;
     }
 
+    pkill_list = HeapAlloc(GetProcessHeap(), 0, pid_list_size * sizeof(DWORD));
+    if (!pkill_list)
+        return 1;
+
     for (i = 0; i < task_count; i++)
     {
         WCHAR *p = task_list[i];
         BOOL is_numeric = TRUE;
+        DWORD pkill_size = 0, index = 0;
+
+        memset(pkill_list, 0, pid_list_size * sizeof(DWORD));
 
         /* Determine whether the string is not numeric. */
         while (*p)
@@ -261,9 +333,43 @@ static int send_close_messages(void)
             }
         }
 
+        // Find processes to kill
         if (is_numeric)
         {
-            DWORD pid = atoiW(task_list[i]);
+            WCHAR ps_name[MAX_PATH] = { 0 };
+            if (get_process_name_from_pid(atoiW(task_list[i]), ps_name, MAX_PATH))
+            {
+                pkill_list[pkill_size] = atoiW(task_list[i]);
+                pkill_size++;
+            }
+        }
+        else
+        {
+            for (index = 0; index < pid_list_size; index++)
+            {
+                WCHAR process_name[MAX_PATH];
+                if (get_process_name_from_pid(pid_list[index], process_name, MAX_PATH) &&
+                    !strcmpiW(process_name, task_list[i]))
+                {
+                    pkill_list[pkill_size] = pid_list[index];
+                    pkill_size++;
+                }
+            }
+        }
+
+        // Can't find any process same as name or PID
+        if (pkill_size == 0)
+        {
+            taskkill_message_printfW(STRING_SEARCH_FAILED, task_list[i]);
+            status_code = 128;
+            continue;
+        }
+
+        // Try to send close messages to process in `pkill_list`
+        for (index = 0; index < pkill_size; index++)
+        {
+            DWORD pid = pkill_list[index];
+            WCHAR process_name[MAX_PATH] = { 0 };
             struct pid_close_info info = { pid };
 
             if (pid == self_pid)
@@ -273,63 +379,90 @@ static int send_close_messages(void)
                 continue;
             }
 
+            // Send close messages to child first
+            if (kill_child_processes)
+            {
+                send_close_messages_tree(pid);
+            }
+
+            get_process_name_from_pid(pid, process_name, MAX_PATH);
             EnumWindows(pid_enum_proc, (LPARAM)&info);
             if (info.found)
-                taskkill_message_printfW(STRING_CLOSE_PID_SEARCH, pid);
-            else
             {
-                taskkill_message_printfW(STRING_SEARCH_FAILED, task_list[i]);
-                status_code = 128;
-            }
-        }
-        else
-        {
-            DWORD index;
-            BOOL found_process = FALSE;
-
-            for (index = 0; index < pid_list_size; index++)
-            {
-                WCHAR process_name[MAX_PATH];
-
-                if (get_process_name_from_pid(pid_list[index], process_name, MAX_PATH) &&
-                    !strcmpiW(process_name, task_list[i]))
+                if (is_numeric)
                 {
-                    struct pid_close_info info = { pid_list[index] };
-
-                    found_process = TRUE;
-                    if (pid_list[index] == self_pid)
-                    {
-                        taskkill_message(STRING_SELF_TERMINATION);
-                        status_code = 1;
-                        continue;
-                    }
-
-                    EnumWindows(pid_enum_proc, (LPARAM)&info);
-                    taskkill_message_printfW(STRING_CLOSE_PROC_SRCH, process_name, pid_list[index]);
+                    taskkill_message_printfW(STRING_CLOSE_PID_SEARCH, pid);
+                }
+                else
+                {
+                    taskkill_message_printfW(STRING_CLOSE_PROC_SRCH, process_name, pid);
                 }
-            }
-
-            if (!found_process)
-            {
-                taskkill_message_printfW(STRING_SEARCH_FAILED, task_list[i]);
-                status_code = 128;
             }
         }
     }
 
+    HeapFree(GetProcessHeap(), 0, pkill_list);
     HeapFree(GetProcessHeap(), 0, pid_list);
     return status_code;
 }
 
-#endif // __REACTOS__
-
-#ifdef __REACTOS__
-static int terminate_processes(BOOL force_termination)
-#else
-static int terminate_processes(void)
-#endif
+static void terminate_process_tree(DWORD ppid)
 {
-    DWORD *pid_list, pid_list_size;
+    FILETIME parent_creation_time = { 0 };
+    HANDLE h = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
+    PROCESSENTRY32W pe = { 0 };
+    pe.dwSize = sizeof(PROCESSENTRY32W);
+
+    if (!get_pid_creation_time(ppid, &parent_creation_time) || !h)
+    {
+        CloseHandle(h);
+        return;
+    }
+
+    if (Process32FirstW(h, &pe))
+    {
+        do
+        {
+            FILETIME child_creation_time = { 0 };
+
+            if (!get_pid_creation_time(pe.th32ProcessID, &child_creation_time))
+            {
+                continue;
+            }
+
+            // Compare creation time to avoid reuse PID, thanks to @ThFabba
+            if (pe.th32ParentProcessID == ppid &&
+                CompareFileTime(&parent_creation_time, &child_creation_time) < 0)
+            {
+                HANDLE process = INVALID_HANDLE_VALUE;
+
+                // Use recursion to browse all child processes
+                terminate_process_tree(pe.th32ProcessID);
+                process = OpenProcess(PROCESS_TERMINATE, FALSE, pe.th32ProcessID);
+                if (!process)
+                {
+                    continue;
+                }
+
+                if (!TerminateProcess(process, 0))
+                {
+                    taskkill_message_printfW(STRING_TERM_CHILD_FAILED, pe.th32ProcessID, ppid);
+                    CloseHandle(process);
+                    continue;
+                }
+
+                taskkill_message_printfW(STRING_TERM_CHILD, pe.th32ProcessID, ppid);
+                CloseHandle(process);
+            }
+        } while (Process32NextW(h, &pe));
+    }
+
+    CloseHandle(h);
+}
+
+static int terminate_processes(void)
+{
+    DWORD *pid_list, pid_list_size, *pkill_list;
     DWORD self_pid = GetCurrentProcessId();
     unsigned int i;
     int status_code = 0;
@@ -341,10 +474,17 @@ static int terminate_processes(void)
         return 1;
     }
 
+    pkill_list = HeapAlloc(GetProcessHeap(), 0, pid_list_size * sizeof(DWORD));
+    if (!pkill_list)
+        return 1;
+
     for (i = 0; i < task_count; i++)
     {
         WCHAR *p = task_list[i];
         BOOL is_numeric = TRUE;
+        DWORD pkill_size = 0, index = 0;
+
+        memset(pkill_list, 0, pid_list_size * sizeof(DWORD));
 
         /* Determine whether the string is not numeric. */
         while (*p)
@@ -356,12 +496,44 @@ static int terminate_processes(void)
             }
         }
 
+        // Find processes to kill
         if (is_numeric)
         {
-            DWORD pid = atoiW(task_list[i]);
-#ifndef __REACTOS__
-            HANDLE process;
-#endif
+            WCHAR ps_name[MAX_PATH] = { 0 };
+            if (get_process_name_from_pid(atoiW(task_list[i]), ps_name, MAX_PATH))
+            {
+                pkill_list[pkill_size] = atoiW(task_list[i]);
+                pkill_size++;
+            }
+        }
+        else
+        {
+            for (index = 0; index < pid_list_size; index++)
+            {
+                WCHAR process_name[MAX_PATH];
+                if (get_process_name_from_pid(pid_list[index], process_name, MAX_PATH) &&
+                    !strcmpiW(process_name, task_list[i]))
+                {
+                    pkill_list[pkill_size] = pid_list[index];
+                    pkill_size++;
+                }
+            }
+        }
+
+        // Can't find any process same as name or PID
+        if (!pkill_size)
+        {
+            taskkill_message_printfW(STRING_SEARCH_FAILED, task_list[i]);
+            status_code = 128;
+            continue;
+        }
+
+        // Try to terminate to process in `pkill_list`
+        for (index = 0; index < pkill_size; index++)
+        {
+            DWORD pid = pkill_list[index];
+            WCHAR process_name[MAX_PATH] = { 0 };
+            HANDLE process = INVALID_HANDLE_VALUE;
 
             if (pid == self_pid)
             {
@@ -370,13 +542,14 @@ static int terminate_processes(void)
                 continue;
             }
 
-#ifdef __REACTOS__
-            if (force_termination)
+            // Terminate child first
+            if (kill_child_processes)
             {
-            HANDLE process;
-#endif
+                terminate_process_tree(pid);
+            }
+
             process = OpenProcess(PROCESS_TERMINATE, FALSE, pid);
-            if (!process)
+            if (get_process_name_from_pid(pid, process_name, MAX_PATH) && !process)
             {
                 taskkill_message_printfW(STRING_SEARCH_FAILED, task_list[i]);
                 status_code = 128;
@@ -385,102 +558,25 @@ static int terminate_processes(void)
 
             if (!TerminateProcess(process, 0))
             {
-                taskkill_message_printfW(STRING_TERMINATE_FAILED, task_list[i]);
+                taskkill_message_printfW(STRING_TERMINATE_FAILED, process_name);
                 status_code = 1;
                 CloseHandle(process);
                 continue;
             }
 
-            taskkill_message_printfW(STRING_TERM_PID_SEARCH, pid);
-            CloseHandle(process);
-#ifdef __REACTOS__
+            if (is_numeric)
+            {
+                taskkill_message_printfW(STRING_TERM_PID_SEARCH, pid);
             }
             else
             {
-                struct pid_close_info info = { pid };
-
-                EnumWindows(pid_enum_proc, (LPARAM)&info);
-                if (info.found)
-                    taskkill_message_printfW(STRING_CLOSE_PID_SEARCH, pid);
-                else
-                {
-                    taskkill_message_printfW(STRING_SEARCH_FAILED, task_list[i]);
-                    status_code = 128;
-                }
-            }
-#endif
-        }
-        else
-        {
-            DWORD index;
-            BOOL found_process = FALSE;
-
-            for (index = 0; index < pid_list_size; index++)
-            {
-                WCHAR process_name[MAX_PATH];
-
-                if (get_process_name_from_pid(pid_list[index], process_name, MAX_PATH) &&
-                    !strcmpiW(process_name, task_list[i]))
-                {
-#ifdef __REACTOS__
-                    found_process = TRUE;
-#else
-                    HANDLE process;
-#endif
-
-                    if (pid_list[index] == self_pid)
-                    {
-                        taskkill_message(STRING_SELF_TERMINATION);
-                        status_code = 1;
-                        continue;
-                    }
-
-#ifdef __REACTOS__
-                    if (force_termination)
-                    {
-                    HANDLE process;
-#endif
-                    process = OpenProcess(PROCESS_TERMINATE, FALSE, pid_list[index]);
-                    if (!process)
-                    {
-                        taskkill_message_printfW(STRING_SEARCH_FAILED, task_list[i]);
-                        status_code = 128;
-                        continue;
-                    }
-
-                    if (!TerminateProcess(process, 0))
-                    {
-                        taskkill_message_printfW(STRING_TERMINATE_FAILED, task_list[i]);
-                        status_code = 1;
-                        CloseHandle(process);
-                        continue;
-                    }
-
-#ifndef __REACTOS__
-                    found_process = TRUE;
-#endif
-                    taskkill_message_printfW(STRING_TERM_PROC_SEARCH, task_list[i], pid_list[index]);
-                    CloseHandle(process);
-#ifdef __REACTOS__
-                    }
-                    else
-                    {
-                        struct pid_close_info info = { pid_list[index] };
-                        EnumWindows(pid_enum_proc, (LPARAM)&info);
-                        taskkill_message_printfW(STRING_CLOSE_PROC_SRCH, process_name, pid_list[index]);
-                    }
-#endif
-                }
-            }
-
-            if (!found_process)
-            {
-                taskkill_message_printfW(STRING_SEARCH_FAILED, task_list[i]);
-                status_code = 128;
+                taskkill_message_printfW(STRING_TERM_PROC_SEARCH, process_name, pid);
             }
+            CloseHandle(process);
         }
     }
 
+    HeapFree(GetProcessHeap(), 0, pkill_list);
     HeapFree(GetProcessHeap(), 0, pid_list);
     return status_code;
 }
@@ -535,10 +631,6 @@ static int get_argument_type(WCHAR* argument)
     return OP_PARAM_INVALID;
 }
 
-/* FIXME
-argument T not supported
-*/
-
 static BOOL process_arguments(int argc, WCHAR* argv[])
 {
     BOOL has_im = FALSE, has_pid = FALSE, has_help = FALSE;
@@ -612,7 +704,14 @@ static BOOL process_arguments(int argc, WCHAR* argv[])
             }
             case OP_PARAM_TERMINATE_CHILD:
             {
-                WINE_FIXME("argument T not supported\n");
+                if (kill_child_processes == TRUE)
+                {
+                    // -t already specified
+                    taskkill_message_printfW(STRING_PARAM_TOO_MUCH, argv[i], 1);
+                    taskkill_message(STRING_USAGE);
+                    return FALSE;
+                }
+                kill_child_processes = TRUE;
                 break;
             }
             case OP_PARAM_INVALID:
@@ -691,8 +790,8 @@ static BOOL process_arguments(int argc, WCHAR *argv[])
             argdata++;
 
             if (!strcmpiW(opTerminateChildren, argdata))
-                WINE_FIXME("argument T not supported\n");
-            if (!strcmpiW(opForceTerminate, argdata))
+                kill_child_processes = TRUE;
+            else if (!strcmpiW(opForceTerminate, argdata))
                 force_termination = TRUE;
             /* Options /IM and /PID appear to behave identically, except for
              * the fact that they cannot be specified at the same time. */
@@ -751,14 +850,10 @@ int wmain(int argc, WCHAR *argv[])
         return 1;
     }
 
-#ifdef __REACTOS__
-    status_code = terminate_processes(force_termination);
-#else
     if (force_termination)
         status_code = terminate_processes();
     else
         status_code = send_close_messages();
-#endif
 
     HeapFree(GetProcessHeap(), 0, task_list);
     return status_code;
diff --git a/base/applications/cmdutils/taskkill/taskkill.h b/base/applications/cmdutils/taskkill/taskkill.h
index 03312fa8c9c..68f84fe8159 100644
--- a/base/applications/cmdutils/taskkill/taskkill.h
+++ b/base/applications/cmdutils/taskkill/taskkill.h
@@ -35,6 +35,8 @@
 #define STRING_ENUM_FAILED      112
 #define STRING_TERMINATE_FAILED 113
 #define STRING_SELF_TERMINATION 114
-#define STRING_PARAM_TOO_MUCH   115
-#define STRING_INVALID_SYNTAX   116
-
+#define STRING_CLOSE_CHILD      115
+#define STRING_TERM_CHILD       116
+#define STRING_TERM_CHILD_FAILED 117
+#define STRING_PARAM_TOO_MUCH   118
+#define STRING_INVALID_SYNTAX   119