How to determine if the executing program was compiled for 64 bit?

Question

I need for my program to determine if it was compiled for 32 bit windows or 64 bit/any CPU. I need to choose a different COM server flag depending on the compilation options. Any ideas?

Answer 1

Checking at run time if you are running a 64-bit application:

To see whether your process is 64-bit or 32-bit you can simply check the IntPtr.Size or any other pointer type. If you get 4 then you are running on 32-bit. If you get 8 then you are running on 64-bit.

What type of computer is your process running as:

You can check the PROCESSOR_ARCHITECTURE environment variable to see if you are running on an x64, ia64 or x86 machine.

Is your process running under emulation:

The Win32 API IsWow64Process will tell you if you are running a 32-bit application under x64. Wow64 means windows32 on windows64.

Contrary to what other people have posted: IsWow64Process will not tell you if you are running a 32-bit or a 64bit application. On 32-bit machines it will tell you FALSE for 32-bit applications when run, and on a 64-bit machine it will tell you TRUE for a 32-bit application. It only tells you if your application is running under emulation.

Answer 2

Are you aware of Environment.Is64BitProcess? It determines whether the current running process is a 64-bit process.

Answer 3

You want the CORFLAGS command-line app from Microsoft. http://msdn.microsoft.com/en-us/library/ms164699(VS.80).aspx