diff --git a/base/applications/dxdiag/system.c b/base/applications/dxdiag/system.c
index 849a7a5d4e1..c10df851e4c 100644
--- a/base/applications/dxdiag/system.c
+++ b/base/applications/dxdiag/system.c
@@ -199,26 +199,26 @@ InitializeSystemPage(HWND hwndDlg)
 
     /* set date/time */
     szTime[0] = L'\0';
-    Length = GetDateFormat(LOCALE_SYSTEM_DEFAULT, DATE_LONGDATE, NULL, NULL, szTime, sizeof(szTime) / sizeof(WCHAR));
+    Length = GetDateFormat(LOCALE_SYSTEM_DEFAULT, DATE_LONGDATE, NULL, NULL, szTime, _countof(szTime));
     if (Length)
     {
         szTime[Length-1] = L',';
         szTime[Length++] = L' ';
     }
-    Length = GetTimeFormatW(LOCALE_SYSTEM_DEFAULT, TIME_FORCE24HOURFORMAT|LOCALE_NOUSEROVERRIDE, NULL, NULL, &szTime[Length], (sizeof(szTime) / sizeof(WCHAR)));
-    szTime[199] = L'\0';
+    Length = GetTimeFormatW(LOCALE_SYSTEM_DEFAULT, TIME_FORCE24HOURFORMAT|LOCALE_NOUSEROVERRIDE, NULL, NULL, szTime + Length, _countof(szTime));
+    szTime[_countof(szTime)-1] = L'\0';
     SendDlgItemMessageW(hwndDlg, IDC_STATIC_TIME, WM_SETTEXT, 0, (LPARAM)szTime);
 
     /* set computer name */
     szTime[0] = L'\0';
-    Length = sizeof(szTime) / sizeof(WCHAR);
+    Length = _countof(szTime);
     if (GetComputerNameW(szTime, &Length))
         SendDlgItemMessageW(hwndDlg, IDC_STATIC_COMPUTER, WM_SETTEXT, 0, (LPARAM)szTime);
 
     /* set product name */
     if (GetRegValue(HKEY_LOCAL_MACHINE, L"SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion", L"ProductName", REG_SZ, szOSName, sizeof(szOSName)))
     {
-        if (LoadStringW(hInst, IDS_OS_VERSION, szFormat, sizeof(szFormat) / sizeof(WCHAR)))
+        if (LoadStringW(hInst, IDS_OS_VERSION, szFormat, _countof(szFormat)))
         {
             WCHAR szCpuName[50];
 
@@ -229,14 +229,14 @@ InitializeSystemPage(HWND hwndDlg)
 
             if (GetVersionEx(&VersionInfo))
             {
-                szTime[(sizeof(szTime) / sizeof(WCHAR))-1] = L'\0';
+                szTime[_countof(szTime)-1] = L'\0';
                 wsprintfW(szTime, szFormat, szOSName, szCpuName, VersionInfo.dwMajorVersion, VersionInfo.dwMinorVersion, VersionInfo.dwBuildNumber);
                 SendDlgItemMessageW(hwndDlg, IDC_STATIC_OS, WM_SETTEXT, 0, (LPARAM)szTime);
             }
             else
             {
                 /* If the version of the OS cannot be retrieved for some reason, then just give the OS Name and Architecture */
-                szTime[(sizeof(szTime) / sizeof(WCHAR))-1] = L'\0';
+                szTime[_countof(szTime)-1] = L'\0';
                 wsprintfW(szTime, L"%s %s", szOSName, szCpuName);
                 SendDlgItemMessageW(hwndDlg, IDC_STATIC_OS, WM_SETTEXT, 0, (LPARAM)szTime);
             }
@@ -244,15 +244,15 @@ InitializeSystemPage(HWND hwndDlg)
     }
     else
     {
-        if (LoadStringW(hInst, IDS_VERSION_UNKNOWN, szTime, sizeof(szTime) / sizeof(WCHAR)))
+        if (LoadStringW(hInst, IDS_VERSION_UNKNOWN, szTime, _countof(szTime)))
         {
-            szTime[(sizeof(szTime) / sizeof(WCHAR))-1] = L'\0';
+            szTime[_countof(szTime)-1] = L'\0';
             SendDlgItemMessage(hwndDlg, IDC_STATIC_VERSION, WM_SETTEXT, 0, (LPARAM)szTime);
         }
     }
 
     /* FIXME set product language/local language */
-    if (GetLocaleInfo(LOCALE_SYSTEM_DEFAULT,LOCALE_SLANGUAGE , szTime, sizeof(szTime) / sizeof(WCHAR)))
+    if (GetLocaleInfo(LOCALE_SYSTEM_DEFAULT, LOCALE_SLANGUAGE, szTime, _countof(szTime)))
         SendDlgItemMessageW(hwndDlg, IDC_STATIC_LANG, WM_SETTEXT, 0, (LPARAM)szTime);
 
     /* prepare SMBIOS data */
@@ -266,7 +266,7 @@ InitializeSystemPage(HWND hwndDlg)
                           szTime, _countof(szTime), FALSE);
     if (Length > 0)
     {
-        szTime[199] = L'\0';
+        szTime[_countof(szTime)-1] = L'\0';
         SendDlgItemMessageW(hwndDlg, IDC_STATIC_MANU, WM_SETTEXT, 0, (LPARAM)szTime);
     }
 
@@ -306,13 +306,13 @@ InitializeSystemPage(HWND hwndDlg)
                               szTime + Index, StrLength, TRUE);
         if (Length > 0)
         {
-            if (Index + StrLength > (sizeof(szTime)/sizeof(WCHAR))- 15)
+            if (Index + StrLength > _countof(szTime) - 15)
             {
                 //FIXME  retrieve BiosMajorRelease, BiosMinorRelease
-                //StrLength = wcslen(&szTime[Index]);
+                //StrLength = wcslen(szTime + Index);
                 //szTime[Index+StrLength] = L' ';
-                //wcscpy(&szTime[Index+StrLength], L"Ver: "); //FIXME NON-NLS
-                //szTime[(sizeof(szTime)/sizeof(WCHAR))-1] = L'\0';
+                //wcscpy(szTime + Index + StrLength, L"Ver: "); //FIXME NON-NLS
+                //szTime[_countof(szTime)-1] = L'\0';
             }
             SendDlgItemMessageW(hwndDlg, IDC_STATIC_BIOS, WM_SETTEXT, 0, (LPARAM)szTime);
         }
@@ -329,11 +329,11 @@ InitializeSystemPage(HWND hwndDlg)
         szFormat[0] = L'\0';
         GetSystemInfo(&SysInfo);
         if (SysInfo.dwNumberOfProcessors > 1)
-            LoadStringW(hInst, IDS_FORMAT_MPPROC, szFormat, sizeof(szFormat) / sizeof(WCHAR));
+            LoadStringW(hInst, IDS_FORMAT_MPPROC, szFormat, _countof(szFormat));
         else
-            LoadStringW(hInst, IDS_FORMAT_UNIPROC, szFormat, sizeof(szFormat) / sizeof(WCHAR));
+            LoadStringW(hInst, IDS_FORMAT_UNIPROC, szFormat, _countof(szFormat));
 
-        szFormat[(sizeof(szFormat)/sizeof(WCHAR))-1] = L'\0';
+        szFormat[_countof(szFormat)-1] = L'\0';
         wsprintfW(szTime, szFormat, szDesc, SysInfo.dwNumberOfProcessors);
         SendDlgItemMessageW(hwndDlg, IDC_STATIC_PROC, WM_SETTEXT, 0, (LPARAM)szTime);
     }
@@ -343,36 +343,36 @@ InitializeSystemPage(HWND hwndDlg)
     mem.dwLength = sizeof(mem);
     if (GlobalMemoryStatusEx(&mem))
     {
-        if (LoadStringW(hInst, IDS_FORMAT_MB, szFormat, sizeof(szFormat) / sizeof(WCHAR)))
+        if (LoadStringW(hInst, IDS_FORMAT_MB, szFormat, _countof(szFormat)))
         {
             /* set total mem string */
-            szFormat[(sizeof(szFormat) / sizeof(WCHAR))-1] = L'\0';
+            szFormat[_countof(szFormat)-1] = L'\0';
             wsprintfW(szTime, szFormat, (mem.ullTotalPhys/1048576));
             SendDlgItemMessageW(hwndDlg, IDC_STATIC_MEM, WM_SETTEXT, 0, (LPARAM)szTime);
         }
 
-        if (LoadStringW(hInst, IDS_FORMAT_SWAP, szFormat, sizeof(szFormat) / sizeof(WCHAR)))
+        if (LoadStringW(hInst, IDS_FORMAT_SWAP, szFormat, _countof(szFormat)))
         {
             /* set swap string */
             AvailableBytes = (mem.ullTotalPageFile-mem.ullTotalPhys)/1048576;
             UsedBytes = (mem.ullTotalPageFile-mem.ullAvailPageFile)/1048576;
 
-            szFormat[(sizeof(szFormat) / sizeof(WCHAR))-1] = L'\0';
+            szFormat[_countof(szFormat)-1] = L'\0';
             wsprintfW(szTime, szFormat, (UsedBytes), (AvailableBytes));
             SendDlgItemMessageW(hwndDlg, IDC_STATIC_SWAP, WM_SETTEXT, 0, (LPARAM)szTime);
         }
     }
     /* set directx version string */
     wcscpy(szTime, L"ReactX ");
-    if (GetDirectXVersion(&szTime[7]))
+    if (GetDirectXVersion(szTime + 7))
     {
         SendDlgItemMessage(hwndDlg, IDC_STATIC_VERSION, WM_SETTEXT, 0, (LPARAM)szTime);
     }
     else
     {
-        if (LoadStringW(hInst, IDS_VERSION_UNKNOWN, szTime, sizeof(szTime) / sizeof(WCHAR)))
+        if (LoadStringW(hInst, IDS_VERSION_UNKNOWN, szTime, _countof(szTime)))
         {
-            szTime[(sizeof(szTime) / sizeof(WCHAR))-1] = L'\0';
+            szTime[_countof(szTime)-1] = L'\0';
             SendDlgItemMessage(hwndDlg, IDC_STATIC_VERSION, WM_SETTEXT, 0, (LPARAM)szTime);
         }
     }