Detect whether current Windows version is 32 bit or 64 bit

Solution 1:

To check for a 64-bit 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
)

ProgramFiles(x86) is an environment variable automatically defined by cmd.exe (both 32-bit and 64-bit versions) on Windows 64-bit machines only.

Solution 2:

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;

Solution 3:

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

Solution 4:

From a batch script:

IF PROCESSOR_ARCHITECTURE == x86 AND
   PROCESSOR_ARCHITEW6432 NOT DEFINED THEN
   // OS is 32bit
ELSE
   // OS is 64bit
END IF

Using Windows API:

if (GetSystemWow64Directory(Directory, MaxDirectory) > 0) 
   // OS is 64bit
else
   // OS is 32bit

Sources:

1. HOWTO: Detect Process Bitness
2. GetSystemWow64Directory function