Detect whether current Windows version is 32 bit or 64 bit

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24

65

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 environment variable that would give that information for Windows XP and Windows Vista?

One possible solution

I see that Wikipedia states that the 64-bit version of Windows XP and Windows Vista have a unique environment 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).

Echovirus answered 2/3, 2009 at 2:33 Comment(7)

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 – Landlord 2/3, 2009 at 2:39

Related to #1739485 – Townswoman 27/11, 2011 at 16:17

I posted the MSDN / Perl answer here: #2030539 – Douceur 6/12, 2011 at 21:8

Why not use a new installer? o_O – Fissiparous 24/4, 2012 at 9:27

For Java, see also #4749173 . (In brief, don't rely on os.arch.) – Fealty 23/8, 2013 at 16:35

I see that Wikipedia states that the 64-bit version of Windows XP and Windows Vista have a unique environment variable: %ProgramW6432%, so I'm guessing that'd be empty on 32-bit Windows.

Not quite. Windows XP seems to leave alone references to environment variables it doesn't know about. I.e echo %ProgramW6432% causes %ProgramW6432% to be echoed, rather than a null string. You should still be able to use this however, with a statement like: if "%ProgramW6432%" == "Program Files" echo 64-bit OS detected or if not "%ProgramW6432%" == "Program Files" echo 32-bit OS detected – Lias 12/2, 2014 at 21:29

Also see: #29075173 – Akihito 16/3, 2015 at 10:56

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9

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.

Townswoman answered 27/11, 2011 at 16:9 Comment(8)

I find the referenced KB article somewhat confusing: They look at whether the CPU is 32 or 64 bit, and from that they determine whether you're running 32-bit or 64-bit Windows? I'm pretty sure you can run 32-bit Windows on a 64-bit CPU. Or maybe I'm missing something.. – Snowfall 19/6, 2012 at 13:6

@daniel kullmann: Obviously the key will be faked to be X86 as the microsoft kb articel noticed to use HKLM\SYSTEM\CurrentCongtrolSet\Control\Session Manager\Envirornment to determine the actual processor type. – Endocardial 26/6, 2013 at 14:50

With regards to HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\0... - On a Win7 64 bit box, I have the following values: Identifier = "Intel64 Family 6 Model 23 Stepping 6", and Platform ID=1 - On a WinXP 32 box (a VM), I have the following values: Identifier = "x86 Family 6 Model 26 Stepping 5", and Platform ID=1 The point here is not to rely on Platform ID (as it's not always 0x00000020 for x86). – Cuirass 29/1, 2014 at 21:25

On Win8.1x64, Platform ID not exist. But here other key Platform Specific Field 1 which is 0x00000002 (two) – Mclean 17/7, 2014 at 20:33

Having 64bit CPU does not entail running 64 bit windows. I have a laptop with 64bit CPU but 32bit windows preinstalled on it. – Sentimentalize 2/2, 2015 at 18:35

I'm using Window7 x86, Windows 8.1 x64, Windows Xp x86. But I can't find Platform ID on Windows 8.1 and the value is not 0x0000020 on Windows 7 and Windows Xp. – Slattern 28/7, 2017 at 1:40

On Win10 x64 on Intel(R) Xeon(R) CPU E5520 @ 2.27GHz there is no Platform ID but Platform Specific Field 1 with value 1. – Symbolic 9/4, 2020 at 8:9

Note that referenced KB article (Last Updated: Apr 17, 2018) states : Applies to: Microsoft Windows Server 2003 Datacenter Edition (32-bit x86)Microsoft Windows Server 2003 Enterprise Edition (32-bit x86)Microsoft Windows Server 2003 Standard Edition (32-bit x86)Microsoft Windows Server 2003 Web Edition – Symbolic 9/4, 2020 at 8:12

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63

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.

Tayib answered 2/12, 2009 at 13:53 Comment(7)

Are those Environment Variables you're testing there? And by the answer "yes, no", are you answering the question : "Is this the 64 bit version of Windows"? – Echovirus 25/4, 2012 at 13:16

I've just checked on both 32 and 64 bit Windows 7 systems, and it works as advertised. Nice. – Sarene 18/3, 2013 at 18:53

Note that braces for if work in XP+. If you care about Win98 that is ;-). – Dilation 6/5, 2014 at 13:48

It's also simple enough to use without any additional cookbooks with tools such as Chef, which is a bonus. – Ballista 1/10, 2014 at 14:8

Tested, I think this should be the accepted answer. – Bougie 4/4, 2015 at 13:45

On my windows7, this won't work when used in a script inside an if block: "if defined ProgramFiles(x86) (" gives ") was unexpected at this time." And quoting "ProgramFiles(x86)" doesn't work either. – Appanage 4/9, 2016 at 11:16

The variable ProgramFiles(x86) seems to serve interoperability between 32-bit and 64-bit parent and child processes. An SS64.com article Detecting 64 bit vs 32 bit shows tricks to detect 64-bit hardware, OS and processes. ss64.com/nt/syntax-64bit.html – Monoicous 23/2, 2017 at 17:9

L

20

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;

Lettielettish answered 27/10, 2009 at 22:25 Comment(8)

Since stackoverflow is a programming site, this is the programmers answer: using the API intended to answer this question. – Wrap 4/11, 2013 at 18:6

Does it work? Since you test at COMPILE time if the app was build on a 64bit system. Basically, if the app was compiled on 64 bits it will always answer TRUE even, of 32 bits. Am I right? – Akihito 16/3, 2015 at 10:20

Also see: #29075173 – Akihito 16/3, 2015 at 10:56

@Altar no, I'm testing at compile time if the app was built for a 64bit system. You can compile 32-bit programs on a 64-bit system. – Lettielettish 16/3, 2015 at 19:49

blogs.msdn.com/b/oldnewthing/archive/2005/02/01/364563.aspx and MSDN both suggest that this function is always defined in win32 and win64 so the code could be made simpler by just executing IsWow64Process. – Gumption 16/6, 2015 at 11:38

@Gumption MSDN appears to agree with me.. – Lettielettish 16/6, 2015 at 19:12

My point was your whole code bloat could be reduced to just one line of code. – Gumption 18/6, 2015 at 12:53

@Gumption I understand what you are saying, but you are incorrect. Read the msdn link. "Minimum supported client Windows Vista, Windows XP with SP2" -- Win2k, for example, does not have IsWow64Process. The same point is made in the comments of the blog post you linked. – Lettielettish 18/6, 2015 at 20:21

T

14

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:

Townswoman answered 27/11, 2011 at 16:20 Comment(1)

Note my 64bit Win7 machine has PROCESSOR_ARCHITECTURE set to AMD64 – Rollet 25/3, 2014 at 1:4

E

13

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

Echovirus answered 17/3, 2009 at 19:5 Comment(6)

The environment variable you listed in your question was ProgramW6432. Here, you list PROCESSOR_ARCHITEW6432. Which one did you use? – Hectogram 17/3, 2009 at 20:43

Thanks Andrew. I found out about this mistake the hard way: when I had someone test it ;-). Should have been: ProgramW6432 .Fixing it now. – Echovirus 18/3, 2009 at 13:24

I don't have either of these environment variables (ProgramW6432 PROCESSOR_ARCHITEW6432), on my Vista 64. I do have PROCESSOR_ARCHITECTURE, which is set to x86 or AMD64 – Dongdonga 28/8, 2009 at 18:54

Thanks Mike! Now, if I can just figure out if Processor_Architecture is always present on Win 64. – Echovirus 29/8, 2009 at 3:20

Except for PROCESSOR_ARCHITE*, these env variables were added in Win7/Server2008: msdn.microsoft.com/en-us/library/aa384274(VS.85).aspx – Neckband 15/7, 2010 at 11:43

@Mike, @total, @Clay: I do have ProgramW6432, PROCESSOR_ARCHITEW6432 and CommonProgramW6432 on my 64-bit Vista Enterprise SP2, but only in 32-bit command prompt. Whether or not these variables are defined seems to depend on the bitness of the calling process, not the OS bitness. – Philis 1/6, 2011 at 6:29

T

9

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)