How do I tell if my application is running as a 32-bit or 64-bit application?

Question

How do I tell if my application (compiled in Visual Studio 2008 as Any CPU) is running as a 32-bit or 64-bit application?

score 164 · Answer 1 · edited Sep 20 '13 at 08:21

164

If you're using .NET 4.0, it's a one-liner for the current process:

Environment.Is64BitProcess

Reference: Environment.Is64BitProcess Property (MSDN)

edited Sep 20 '13 at 08:21

Peter Mortensen

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answered Aug 11 '10 at 18:25

Sam

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Thanks for posting the answer, that's great to know. I'm not going to change the current accepted answer because this question was originally about .NET 3.5 but I would encourage people to up vote your answer as well. – Redwood Aug 11 '10 at 20:26

score 74 · Accepted Answer · edited Sep 20 '13 at 08:20

74

if (IntPtr.Size == 8) 
{
    // 64 bit machine
} 
else if (IntPtr.Size == 4) 
{
    // 32 bit machine
}

edited Sep 20 '13 at 08:20

Peter Mortensen

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answered Dec 29 '08 at 13:09

Perica Zivkovic

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Doesn't the compiler play any role in between? – mrbubz Apr 22 '14 at 02:04
1

Just for those who are on .NET 4+ - there is a better answer now bellow about Environment.Is64BitProcess – Sevenate Jan 15 '20 at 18:01

score 5 · Answer 3 · answered Nov 05 '08 at 18:09

5

I found this code from Martijn Boven that does the trick:

public static bool Is64BitMode() {
    return System.Runtime.InteropServices.Marshal.SizeOf(typeof(IntPtr)) == 8;
}

answered Nov 05 '08 at 18:09

Redwood

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It's likely more efficient to call IntPtr.Size instead of Marshal.SizeOf(typeof(IntPtr)) – JaredPar Nov 05 '08 at 19:20

score 5 · Answer 4 · edited Sep 29 '14 at 15:51

This code sample from Microsoft All-In-One Code Framework can answer your question:

Detect the process running platform in C# (CSPlatformDetector)

The CSPlatformDetector code sample demonstrates the following tasks related to platform detection:

Detect the name of the current operating system. (e.g. "Microsoft Windows 7 Enterprise")

Detect the version of the current operating system. (e.g. "Microsoft Windows NT 6.1.7600.0")

Determine whether the current operating system is a 64-bit operating system.

Determine whether the current process is a 64-bit process.

Determine whether an arbitrary process running on the system is 64-bit.

If you just want to determine whether the currently running process is a 64-bit process, you can use the Environment.Is64BitProcess property that is new in .NET Framework 4.

And if you want to detect whether an arbitrary application running on the system is a 64-bit process, you need to determine the OS bitness, and if it is 64-bit, call IsWow64Process() with the target process handle:

static bool Is64BitProcess(IntPtr hProcess)
{
    bool flag = false;

    if (Environment.Is64BitOperatingSystem)
    {
        // On 64-bit OS, if a process is not running under Wow64 mode, 
        // the process must be a 64-bit process.
        flag = !(NativeMethods.IsWow64Process(hProcess, out flag) && flag);
    }

    return flag;
}

Can be a useful library, just a bit overkill in this context :). — Gert Arnold, May 17 '12 at 20:30

score 1 · Answer 5 · answered Aug 10 '17 at 15:00

1

In .Net Standard you can use System.Runtime.InteropServices.RuntimeInformation.OSArchitecture

answered Aug 10 '17 at 15:00

Owen Pauling

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Also in .NET Framework since .NET Framework 4.7.1 (from 2017). – Jeppe Stig Nielsen Nov 22 '22 at 11:53

How do I tell if my application is running as a 32-bit or 64-bit application?

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