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 Win DLL call or (even better) an environment variable that would give that info for XP and Vista?

One possible solution

I see that Wikipedia states that the 64 bit version of XP and Vista have a unique Env Variable: * %ProgramW6432%* so I'm guessing that'd be empty on 32 bit windows.

This variable points to Program Files directory, which stores all the installed program of Windows and others. The default on English-language systems is C:\Program Files. In 64-bit editions of Windows (XP, 2003, Vista), there are also %ProgramFiles(x86)% which defaults to C:\Program Files (x86) and %ProgramW6432% which defaults to C:\Program Files. The %ProgramFiles% itself depends on whether the process requesting the environment variable is itself 32-bit or 64-bit (this is caused by Windows-on-Windows 64-bit redirection).

Answer 1

Refer to:

• If you're using .Net: How to detect Windows 64 bit platform with .net?
• If you want to use it outside .Net: How to detect programmatically whether you are running on 64-bit Windows

Answer 2

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!

Answer 3

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 4

In C#:

public bool Is64bit() {
    return Marshal.SizeOf(typeof(IntPtr)) == 8;
}

In VB.Net:

Public Sub Is64bit() As Boolean
    Is64bit = Marshal.SizeOf(GetType(IntPtr)) = 8
End Sub

Answer 5

I tested the solution I suggested in my question:

Tested for Windows Environment Variable: ProgramW6432

If it's non empty then it's 64 bit Windows.W

Answer 6

This has been answered pretty well already, but since the question and current answers helped me come up with my own solution, I'll post it here in the hope that someone else will save some time.

Delphi 7 code to check whether your 32 bit program is running on a 64 bit operating system:

function Is64BitOS: Boolean;
type
  TIsWow64Process = function(Handle:THandle; var IsWow64 : BOOL) : BOOL; stdcall;
var
  hKernel32 : Integer;
  IsWow64Process : TIsWow64Process;
  IsWow64 : BOOL;
begin
  // 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 versions
  // of kernel32.dll (eg. Windows 2000) don't know about it.
  // see http://msdn.microsoft.com/en-us/library/ms684139%28VS.85%29.aspx
  Result := False;
  hKernel32 := LoadLibrary('kernel32.dll');
  if (hKernel32 = 0) then RaiseLastOSError;
  @IsWow64Process := GetProcAddress(hkernel32, 'IsWow64Process');
  if Assigned(IsWow64Process) then begin
    IsWow64 := False;
    if (IsWow64Process(GetCurrentProcess, IsWow64)) then begin
      Result := IsWow64;
    end
    else RaiseLastOSError;
  end;
  FreeLibrary(hKernel32);
end;

Answer 7

To check for 64bit version of Windows in a command box I use the following template:

test.bat:

@echo off
if defined ProgramFiles(x86) (
@echo yes
@echo Some 64-bit work
) else (
@echo no
@echo Some 32-bit work
)

Answer 8

I used this within a login script to detect 64 bit Windows

if "%ProgramW6432%" == "%ProgramFiles%" goto is64flag