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

use GetBinaryType api function and you will have the type of the file

this is the link to the api on msdn http://msdn.microsoft.com/en-us/library/aa364819(VS.85).aspx

the results are:

SCS_32BIT_BINARY = 32 bit exe

SCS_64BIT_BINARY = 64 bit exe

SCS_DOS_BINARY = DOS

SCS_OS216_BINARY = OS/2

SCS_WOW_BINARY = 16 bit

SCS_POSIX_BINARY = POSIX based

SCS_PIF_BINARY = PIF file that execute on DOS

Answer 4

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

Answer 5

You can use the IsWow64Process function to determine at runtime whethehr your COM server is a x64 or win32 process.

If you just want to know this during compile time: the compiler sets the _WIN64 macro.

Answer 6

You could do this based on setting compile time constants and doing #ifs based on those to set a value that you can check to see which platform the application was compiled for. See Target platform/processor at compile time.

The easiest other way is to check the IntPtr.Size property to see if it's 4 (32 bit), or 8 (64 bit).

Answer 7

Take a look at conditional methods.

Answer 8

While it seems like an odd route to go, you can tell whether you're running in 32-bit (or 64-bit in WOW64) or 64-bit .NET code by checking IntPtr.Size.

On 32-bit/WOW64, IntPtr.Size is 4.

On 64-bit, IntPtr.Size is 8.

Source: Migrating 32-bit Managed Code to 64-bit Managed Code on MSDN.

Answer 9

You can use the Predefined Macros to check compilation type

   #if (_WIN64) 
        const bool IS_64 = true;
    #else
       const bool IS_64 = false;
    #endif