Detect whether current Windows version is 32 bit or 64 bit

Question

Believe it or not, my installer is so old that it doesn\'t have an option to detect the 64-bit version of Windows.

Is there a Windows DLL call or (even better) an en

Answer 1

Check the Registry for the existence of HKLM\SOFTWARE\Wow6432Node - If it's there, the system is 64-bit - 32-bit, otherwise.

Answer 2

Another way created by eGerman that uses PE numbers of compiled executables (does not rely on registry records or environment variables):

@echo off &setlocal


call :getPETarget "%SystemRoot%\explorer.exe"


if "%=ExitCode%" EQU "00008664" (
    echo x64
) else (
    if "%=ExitCode%" EQU "0000014C" (
        echo x32
    ) else (
        echo undefined
    )
)


goto :eof


:getPETarget FilePath
:: ~~~~~~~~~~~~~~~~~~~~~~
:: Errorlevel
::   0 Success
::   1 File Not Found
::   2 Wrong Magic Number
::   3 Out Of Scope
::   4 No PE File
:: ~~~~~~~~~~~~~~~~~~~~~~
:: =ExitCode
::   CPU identifier

setlocal DisableDelayedExpansion
set "File=%~1"
set Cmp="%temp%\%random%.%random%.1KB"
set Dmp="%temp%\%random%.%random%.dmp"

REM write 1024 times 'A' into a temporary file
if exist "%File%" (
  >%Cmp% (
    for /l %%i in (1 1 32) do <nul set /p "=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
  )
  setlocal EnableDelayedExpansion
) else (endlocal &cmd /c exit 0 &exit /b 1)

REM generate a HEX dump of the executable file (first 1024 Bytes)
set "X=1"
>!Dmp! (
  for /f "skip=1 tokens=1,2 delims=: " %%i in ('fc /b "!File!" !Cmp!^|findstr /vbi "FC:"') do (
    set /a "Y=0x%%i"
    for /l %%k in (!X! 1 !Y!) do echo 41
    set /a "X=Y+2"
    echo %%j
  )
)
del !Cmp!

REM read certain values out of the HEX dump
set "err="
<!Dmp! (
  set /p "A="
  set /p "B="
  REM magic number has to be "MZ"
  if "!A!!B!" neq "4D5A" (set "err=2") else (
    REM skip next 58 bytes
    for /l %%i in (3 1 60) do set /p "="
    REM bytes 61-64 contain the offset to the PE header in little endian order
    set /p "C="
    set /p "D="
    set /p "E="
    set /p "F="
    REM check if the beginning of the PE header is part of the HEX dump
    if 0x!F!!E!!D!!C! lss 1 (set "err=3") else (
      if 0x!F!!E!!D!!C! gtr 1018 (set "err=3") else (
        REM skip the offset to the PE header
        for /l %%i in (65 1 0x!F!!E!!D!!C!) do set /p "="
        REM next 4 bytes have to contain the signature of the PE header
        set /p "G="
        set /p "H="
        set /p "I="
        set /p "J="
        REM next 2 bytes contain the CPU identifier in little endian order
        set /p "K="
        set /p "L="
      )
    )
  )
)
del !Dmp!
if defined err (endlocal &endlocal &cmd /c exit 0 &exit /b %err%)

REM was the signature ("PE\0\0") of the PE header found
if "%G%%H%%I%%J%"=="50450000" (
  REM calculate the decimal value of the CPU identifier
  set /a "CPUID=0x%L%%K%"
) else (endlocal &endlocal &cmd /c exit 0 &exit /b 4)
endlocal &endlocal &cmd /c exit %CPUID% &exit /b 0

Answer 3

See the batch script listed in How To Check If Computer Is Running A 32 Bit or 64 Bit Operating System. It also includes instructions for checking this from the Registry:

You can use the following registry location to check if computer is running 32 or 64 bit of Windows operating system:

HKLM\HARDWARE\DESCRIPTION\System\CentralProcessor\0

You will see the following registry entries in the right pane:

Identifier     REG_SZ             x86 Family 6 Model 14 Stepping 12
Platform ID    REG_DWORD          0x00000020(32)

The above “x86” and “0x00000020(32)” indicate that the operating system version is 32 bit.

Answer 4

Here is some Delphi code to check whether your program is running on a 64 bit operating system:

function Is64BitOS: Boolean;
{$IFNDEF WIN64}
type
  TIsWow64Process = function(Handle:THandle; var IsWow64 : BOOL) : BOOL; stdcall;
var
  hKernel32 : Integer;
  IsWow64Process : TIsWow64Process;
  IsWow64 : BOOL;
{$ENDIF}
begin
  {$IFDEF WIN64}
     //We're a 64-bit application; obviously we're running on 64-bit Windows.
     Result := True;
  {$ELSE}
  // We can check if the operating system is 64-bit by checking whether
  // we are running under Wow64 (we are 32-bit code). We must check if this
  // function is implemented before we call it, because some older 32-bit 
  // versions of kernel32.dll (eg. Windows 2000) don't know about it.
  // See "IsWow64Process", http://msdn.microsoft.com/en-us/library/ms684139.aspx
  Result := False;
  hKernel32 := LoadLibrary('kernel32.dll');
  if hKernel32 = 0 then RaiseLastOSError;
  try
    @IsWow64Process := GetProcAddress(hkernel32, 'IsWow64Process');
    if Assigned(IsWow64Process) then begin
      if (IsWow64Process(GetCurrentProcess, IsWow64)) then begin
        Result := IsWow64;
      end
      else RaiseLastOSError;
    end;
  finally
    FreeLibrary(hKernel32);
  end;  
  {$ENDIf}
end;

Answer 5

I don't know what language you're using, but .NET has the environment variable PROCESSOR_ARCHITEW6432 if the OS is 64-bit.

If all you want to know is whether your application is running 32-bit or 64-bit, you can check IntPtr.Size. It will be 4 if running in 32-bit mode and 8 if running in 64-bit mode.

Answer 6

If you can make API calls, try using GetProcAddress / GetModuleHandle to check for the existence of IsWow64Process which is only present in Windows OS that have 64-bit versions.

You could also try the ProgramFiles(x86) environment variable used in Vista/2008 for backwards compatibility, but I'm not 100% sure about XP-64 or 2003-64.

Good luck!