diff --git a/rostests/winetests/setupapi/CMakeLists.txt b/rostests/winetests/setupapi/CMakeLists.txt
index 0e9a1586671..c314cffaabf 100644
--- a/rostests/winetests/setupapi/CMakeLists.txt
+++ b/rostests/winetests/setupapi/CMakeLists.txt
@@ -1,6 +1,7 @@
 
 list(APPEND SOURCE
     devinst.c
+    dialog.c
     diskspace.c
     install.c
     misc.c
diff --git a/rostests/winetests/setupapi/dialog.c b/rostests/winetests/setupapi/dialog.c
new file mode 100644
index 00000000000..973b1fca1fe
--- /dev/null
+++ b/rostests/winetests/setupapi/dialog.c
@@ -0,0 +1,107 @@
+/*
+ * Unit tests for SetupPromptForDisk
+ *
+ * Copyright 2014 Michael Müller
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+#include <stdarg.h>
+
+#include "windef.h"
+#include "winbase.h"
+#include "wingdi.h"
+#include "winuser.h"
+#include "winreg.h"
+#include "guiddef.h"
+#include "setupapi.h"
+
+#include "wine/test.h"
+
+static void test_SetupPromptForDiskA(void)
+{
+    char path[] = "C:\\windows\\system32";
+    char file[] = "kernel32.dll";
+    char buffer[MAX_PATH];
+    UINT ret;
+    DWORD length;
+
+    memset(buffer, 0, sizeof(buffer));
+    ret = SetupPromptForDiskA(0, "Test", "Testdisk", path, file, 0, IDF_CHECKFIRST, buffer, sizeof(buffer) - 1, &length);
+    ok(ret == DPROMPT_SUCCESS, "Expected DPROMPT_SUCCESS, got %u\n", ret);
+    ok(length == strlen(path)+1, "Expect length %u, got %u\n", (DWORD)strlen(path) + 1, length);
+    ok(strcmp(path, buffer) == 0, "Expected path %s, got %s\n", path, buffer);
+
+    memset(buffer, 0, sizeof(buffer));
+    ret = SetupPromptForDiskA(0, "Test", "Testdisk", path, file, 0, IDF_CHECKFIRST, 0, 0, &length);
+    ok(ret == DPROMPT_SUCCESS, "Expected DPROMPT_SUCCESS, got %d\n", ret);
+    ok(length == strlen(path)+1, "Expect length %u, got %u\n", (DWORD)strlen(path) + 1, length);
+
+    memset(buffer, 0, sizeof(buffer));
+    ret = SetupPromptForDiskA(0, "Test", "Testdisk", path, file, 0, IDF_CHECKFIRST, buffer, 1, &length);
+    ok(ret == DPROMPT_BUFFERTOOSMALL, "Expected DPROMPT_BUFFERTOOSMALL, got %u\n", ret);
+
+    memset(buffer, 0, sizeof(buffer));
+    ret = SetupPromptForDiskA(0, "Test", "Testdisk", path, file, 0, IDF_CHECKFIRST, buffer, strlen(path), &length);
+    ok(ret == DPROMPT_BUFFERTOOSMALL, "Expected DPROMPT_BUFFERTOOSMALL, got %u\n", ret);
+
+    memset(buffer, 0, sizeof(buffer));
+    ret = SetupPromptForDiskA(0, "Test", "Testdisk", path, file, 0, IDF_CHECKFIRST, buffer, strlen(path)+1, &length);
+    ok(ret == DPROMPT_SUCCESS, "Expected DPROMPT_SUCCESS, got %u\n", ret);
+    ok(length == strlen(path)+1, "Expect length %u, got %u\n", (DWORD)strlen(path) + 1, length);
+    ok(strcmp(path, buffer) == 0, "Expected path %s, got %s\n", path, buffer);
+}
+
+static void test_SetupPromptForDiskW(void)
+{
+    WCHAR path[] = {'C',':','\\','w','i','n','d','o','w','s','\\','s','y','s','t','e','m','3','2','\0'};
+    WCHAR file[] = {'k','e','r','n','e','l','3','2','.','d','l','l','\0'};
+    WCHAR title[] = {'T','e','s','t','\0'};
+    WCHAR disk[] = {'T','e','s','t','d','i','s','k','\0'};
+    WCHAR buffer[MAX_PATH];
+    UINT ret;
+    DWORD length;
+
+    memset(buffer, 0, sizeof(buffer));
+    ret = SetupPromptForDiskW(0, title, disk, path, file, 0, IDF_CHECKFIRST, buffer, MAX_PATH-1, &length);
+    ok(ret == DPROMPT_SUCCESS, "Expected DPROMPT_SUCCESS, got %u\n", ret);
+    ok(length == lstrlenW(path)+1, "Expect length %u, got %u\n", lstrlenW(path)+1, length);
+    ok(lstrcmpW(path, buffer) == 0, "Expected path %s, got %s\n", wine_dbgstr_w(path), wine_dbgstr_w(buffer));
+
+    memset(buffer, 0, sizeof(buffer));
+    ret = SetupPromptForDiskW(0, title, disk, path, file, 0, IDF_CHECKFIRST, 0, 0, &length);
+    ok(ret == DPROMPT_SUCCESS, "Expected DPROMPT_SUCCESS, got %d\n", ret);
+    ok(length == lstrlenW(path)+1, "Expect length %u, got %u\n", lstrlenW(path)+1, length);
+
+    memset(buffer, 0, sizeof(buffer));
+    ret = SetupPromptForDiskW(0, title, disk, path, file, 0, IDF_CHECKFIRST, buffer, 1, &length);
+    ok(ret == DPROMPT_BUFFERTOOSMALL, "Expected DPROMPT_BUFFERTOOSMALL, got %u\n", ret);
+
+    memset(buffer, 0, sizeof(buffer));
+    ret = SetupPromptForDiskW(0, title, disk, path, file, 0, IDF_CHECKFIRST, buffer, lstrlenW(path), &length);
+    ok(ret == DPROMPT_BUFFERTOOSMALL, "Expected DPROMPT_BUFFERTOOSMALL, got %u\n", ret);
+
+    memset(buffer, 0, sizeof(buffer));
+    ret = SetupPromptForDiskW(0, title, disk, path, file, 0, IDF_CHECKFIRST, buffer, lstrlenW(path)+1, &length);
+    ok(ret == DPROMPT_SUCCESS, "Expected DPROMPT_SUCCESS, got %u\n", ret);
+    ok(length == lstrlenW(path)+1, "Expect length %u, got %u\n", lstrlenW(path)+1, length);
+    ok(lstrcmpW(path, buffer) == 0, "Expected path %s, got %s\n", wine_dbgstr_w(path), wine_dbgstr_w(buffer));
+}
+
+START_TEST(dialog)
+{
+    test_SetupPromptForDiskA();
+    test_SetupPromptForDiskW();
+}
\ No newline at end of file
diff --git a/rostests/winetests/setupapi/install.c b/rostests/winetests/setupapi/install.c
index fdee52424fc..d12d6839a29 100644
--- a/rostests/winetests/setupapi/install.c
+++ b/rostests/winetests/setupapi/install.c
@@ -63,10 +63,12 @@ static BOOL (WINAPI *pSetupGetInfFileListW)(PCWSTR, DWORD, PWSTR, DWORD, PDWORD)
 static void create_inf_file(LPCSTR filename, const char *data)
 {
     DWORD res;
+    BOOL ret;
     HANDLE handle = CreateFileA(filename, GENERIC_WRITE, 0, NULL,
                            CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
     assert(handle != INVALID_HANDLE_VALUE);
-    assert(WriteFile(handle, data, strlen(data), &res, NULL));
+    ret = WriteFile(handle, data, strlen(data), &res, NULL);
+    assert(ret != 0);
     CloseHandle(handle);
 }
 
@@ -718,6 +720,64 @@ static void test_inffilelist(void)
     RemoveDirectoryA(dirA);
 }
 
+static const char dirid_inf[] = "[Version]\n"
+    "Signature=\"$Chicago$\"\n"
+    "[DefaultInstall]\n"
+    "AddReg=Add.Settings\n"
+    "[Add.Settings]\n"
+    "HKCU,Software\\Wine\\setupapitest,dirid,,%%%i%%\n";
+
+static void check_dirid(int dirid, LPCSTR expected)
+{
+    char buffer[sizeof(dirid_inf)+11];
+    char path[MAX_PATH], actual[MAX_PATH];
+    LONG ret;
+    DWORD size, type;
+    HKEY key;
+
+    sprintf(buffer, dirid_inf, dirid);
+
+    create_inf_file(inffile, buffer);
+
+    sprintf(path, "%s\\%s", CURR_DIR, inffile);
+    run_cmdline("DefaultInstall", 128, path);
+
+    size = sizeof(actual);
+    actual[0] = '\0';
+    ret = RegOpenKeyA(HKEY_CURRENT_USER, "Software\\Wine\\setupapitest", &key);
+    if (ret == ERROR_SUCCESS)
+    {
+        ret = RegQueryValueExA(key, "dirid", NULL, &type, (BYTE*)&actual, &size);
+        RegCloseKey(key);
+        if (type != REG_SZ)
+            ret = ERROR_FILE_NOT_FOUND;
+    }
+
+    ok(ret == ERROR_SUCCESS, "Failed getting value for dirid %i, err=%d\n", dirid, ret);
+    ok(!strcmp(actual, expected), "Expected path for dirid %i was \"%s\", got \"%s\"\n", dirid, expected, actual);
+
+    ok_registry(TRUE);
+    ret = DeleteFileA(inffile);
+    ok(ret, "Expected source inf to exist, last error was %d\n", GetLastError());
+}
+
+/* Test dirid values */
+static void test_dirid(void)
+{
+    char expected[MAX_PATH];
+
+    check_dirid(DIRID_NULL, "");
+
+    GetWindowsDirectoryA(expected, MAX_PATH);
+    check_dirid(DIRID_WINDOWS, expected);
+
+    GetSystemDirectoryA(expected, MAX_PATH);
+    check_dirid(DIRID_SYSTEM, expected);
+
+    strcat(expected, "\\unknown");
+    check_dirid(40, expected);
+}
+
 START_TEST(install)
 {
     HMODULE hsetupapi = GetModuleHandleA("setupapi.dll");
@@ -768,6 +828,7 @@ START_TEST(install)
         test_registry();
         test_install_svc_from();
         test_driver_install();
+        test_dirid();
 
         UnhookWindowsHookEx(hhook);
 
diff --git a/rostests/winetests/setupapi/testlist.c b/rostests/winetests/setupapi/testlist.c
index ccf33787079..895715aa95c 100644
--- a/rostests/winetests/setupapi/testlist.c
+++ b/rostests/winetests/setupapi/testlist.c
@@ -4,6 +4,7 @@
 #include <wine/test.h>
 
 extern void func_devinst(void);
+extern void func_dialog(void);
 extern void func_diskspace(void);
 extern void func_install(void);
 extern void func_misc(void);
@@ -15,6 +16,7 @@ extern void func_stringtable(void);
 const struct test winetest_testlist[] =
 {
     { "devinst", func_devinst },
+    { "dialog", func_dialog },
     { "diskspace", func_diskspace },
     { "install", func_install },
     { "misc", func_misc },