Programmatically determine whether Windows is 32 or 64 bit.

[rafter109]

I am trying to write a launcher that will call up the appropriate installer for a user's system. I am aware of how to determine what verison of Windows such as 2k, XP, Vista, etc. but I am having trouble figuring out how to determine programmatically whether the installed OS is 32 or 64 bit. I would like to do it from the command prompt if possible but any language that would not require me to pre-install libraries on the users computer would also work. Any help would be appreciated.

[lnmnky]

Anyhelp?

http://social.msdn.microsoft.com/Forums/en...14-d89550c3fc3b

[Prince Charming]

You could check if the environment variable %ProgramW6432% resolves to a path, which should be \Program Files on an x86-64 installation of Windows.. It shouldn't exist or resolve on an x86 version of Windows.

[rafter109]

Anyhelp?

http://social.msdn.microsoft.com/Forums/en...14-d89550c3fc3b

These methods only work on Vista and XP SP2, I need the program to function fully on any version of windows from 2000 to present.

[Budious]

http://blogs.msdn.com/david.wang/archive/2...ss-Bitness.aspx

[MagicAndre1981]

use GetNativeSystemInfo.

[Eric Veteran]

What language are you wanting to do this in? There's a big difference depending on the context. :)

[lnmnky]

Well only perform that test on a platform that supports it.

You can try/catch and handle any errors.

Test for platform and then test for 32/64 version after that if needed.

[hdood]

Yes, we have to know the language to answer the question.

The environment variable PROCESSOR_ARCHITECTURE will be either AMD64 or x86 (which can again have PROCESSOR_ARCHITEW6432 set if the 32-bit program is actually running on a 64-bit OS), but I don't know if that counts as "programatically."

In managed code you can just check the size of IntPtr. It will be 4 for 32-bit and 8 for 64-bit.

[Lannister]

Might be .NET related, but Paint.Net uses one installer but it will install either for 32bit or 64bit depending on your OS. Might be worth asking in their forums.

[rafter109]

Guess I need to add a little more context to this post.

I am building a CD with an autorun. The software publisher has 2 seperate installers for 64 and 32 bit environments. I am looking to have a very simple (hopefully batch) application that will determine which installer to use on the given system. I am willing to use a 3rd party utility as long as it is released free and the publisher does not mind redistribution.

[hdood]

I don't see why they can't do it themselves? It's just a few lines of C code, compiled as a 32-bit program.

typedef BOOL (WINAPI *IW64PFP)(HANDLE, BOOL *);

BOOL is64bit()
{
	BOOL res = FALSE;
	IW64PFP  IW64P = (IW64PFP)GetProcAddress(GetModuleHandle(L"kernel32"), "IsWow64Process");

	if(IW64P != NULL)
	{
		IW64P(GetCurrentProcess(), &res);
	}

	return res;
}

Then just do whatever you want depending on the result. Also, remember to sign the program with a digital certificate.

If you really want it to just be a batch file though, something like this would work:

@echo off
if "%PROCESSOR_ARCHITECTURE%" == "x86" (
	@start 32bitinstaller.exe
) else (
	if "%PROCESSOR_ARCHITECTURE%" == "AMD64" (
		@start 64bitinstaller.exe
	) else (
		echo Unsupported platform.
		@pause
	)
)
@exit

Edited May 17, 2009 by hdood

[Eric Veteran]

hdhood's batch file example should be perfect for what you clarified you want to do. :)

@ Lannister: .NET apps are generally generated at runtime or at install-time with NGEN so one installer can create native apps for both architectures.

[rafter109]

Thanks hdood. Your batch example was exactly what I needed. Coupled with ver to ensure that the operating system is one of the supported oses for the app I have everything I need. Thanks for everyones prompt responses.