How to determine programmatically whether a particular process is 32-bit or 64-bit

Question

How can my C# application check whether a particular application/process (note: not the current process) is running in 32-bit or 64-bit mode?

For example, I might want to query a particular process by name, i.e, 'abc.exe', or based on the process ID number.

Please always put the language in as a tag; I'll change that now on this post. :-) — Dean J, Dec 23 '09 at 15:21
Please clarify whether you want to know the **current** process is 64 bit or you are querying another process? — Mehrdad Afshari, Dec 23 '09 at 15:25
Dupelicate: http://stackoverflow.com/questions/266082/how-do-i-tell-if-my-application-is-running-as-a-32-or-64-bit-application — Redwood, Dec 23 '09 at 17:02

Jesse C. Slicer · Accepted Answer · 2015-11-23T22:07:01.567

195

One of the more interesting ways I've seen is this:

if (IntPtr.Size == 4)
{
    // 32-bit
}
else if (IntPtr.Size == 8)
{
    // 64-bit
}
else
{
    // The future is now!
}

To find out if OTHER processes are running in the 64-bit emulator (WOW64), use this code:

namespace Is64Bit
{
    using System;
    using System.ComponentModel;
    using System.Diagnostics;
    using System.Runtime.InteropServices;

    internal static class Program
    {
        private static void Main()
        {
            foreach (var p in Process.GetProcesses())
            {
                try
                {
                    Console.WriteLine(p.ProcessName + " is " + (p.IsWin64Emulator() ? string.Empty : "not ") + "32-bit");
                }
                catch (Win32Exception ex)
                {
                    if (ex.NativeErrorCode != 0x00000005)
                    {
                        throw;
                    }
                }
            }

            Console.ReadLine();
        }

        private static bool IsWin64Emulator(this Process process)
        {
            if ((Environment.OSVersion.Version.Major > 5)
                || ((Environment.OSVersion.Version.Major == 5) && (Environment.OSVersion.Version.Minor >= 1)))
            {
                bool retVal;

                return NativeMethods.IsWow64Process(process.Handle, out retVal) && retVal;
            }

            return false; // not on 64-bit Windows Emulator
        }
    }

    internal static class NativeMethods
    {
        [DllImport("kernel32.dll", SetLastError = true, CallingConvention = CallingConvention.Winapi)]
        [return: MarshalAs(UnmanagedType.Bool)]
        internal static extern bool IsWow64Process([In] IntPtr process, [Out] out bool wow64Process);
    }
}

edited Nov 23 '15 at 22:07

answered Dec 23 '09 at 15:24

Jesse C. Slicer

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`(Environment.OSVersion.Version.Major >= 5 && Environment.OSVersion.Version.Minor >= 1)` And that is why Microsoft has to create version lie compatibility shims - to work around bugs in code like that. What happens when Windows Vista (6.0) comes out? And people then bad-mouth Microsoft for making Windows 7 version 6.1 rather than 7.0, it fixes so many app-compat bugs. – Ian Boyd Sep 09 '10 at 14:53
the [Out] out bool wow64Process should be [Out] out Int32 wow64Process because the native function's BOOL maps to Int32 – zhaorufei Jun 29 '11 at 05:29
@赵如飞: no. It's a pointer to a boolean. The authoritative source: http://msdn.microsoft.com/en-us/library/ms684139 – Jesse C. Slicer Jun 29 '11 at 13:05
4

Function name IsWin64 is a bit misleading, I think. It returns true if 32-bit process is running under x64 OS. – Denis The Menace Apr 22 '13 at 09:00
2

Why use `processHandle = Process.GetProcessById(process.Id).Handle;` instead of just `processHandle = process.Handle;` ? – Jonathon Reinhart Jun 21 '14 at 15:32
1

@JonathonReinhart well isn't that just a good question. I have no idea. It must have been vestigial from a switching around of doing things one way to another. Thanks for finding that! – Jesse C. Slicer Jun 21 '14 at 16:05
2

This answer is just incorrect; and returning false instead of raising an exception in a case of error is a very bad design. – user626528 Oct 19 '15 at 03:01
It is used for only 64Bit system.This logic fail in 32 Bit System – Nitin Parashar Jul 13 '18 at 10:46

score 154 · Answer 2 · edited May 18 '17 at 12:50

154

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

Environment.Is64BitProcess

See Environment.Is64BitProcessProperty (MSDN).

edited May 18 '17 at 12:50

Hakan Fıstık

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answered Aug 11 '10 at 18:22

Sam

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Could you post the code of `Is64BitProcess`? Perhaps i can use what it does to figure out if i'm running in as a 64-bit process. – Ian Boyd Sep 09 '10 at 14:48
1

@Ian, I doubt Sam would be legally permitted to post MS code on this forum. I'm not sure of the exact content of their reference licence, but I am pretty sure it proscribes reproduction of the code anywhere. – ProfK Mar 28 '11 at 06:43
3

@Ian someone has done that work for you: http://stackoverflow.com/questions/336633/how-to-detect-windows-64-bit-platform-with-net/1913908#1913908 – Robert MacLean Sep 05 '11 at 14:01
5

The OP specifically asked to query *another* process, not the current process. – Harry Johnston Oct 19 '15 at 03:10
1

Note that Microsoft *did* post the code for `Is64BitProcess` ( https://referencesource.microsoft.com/#mscorlib/system/environment.cs). However, it's just a hard-coded return statement, controlled by compilation symbol. – Brian Oct 10 '17 at 18:37

user626528 · Answer 3 · 2021-03-19T22:13:07.050

The selected answer is incorrect as it doesn't do what was asked. It checks if a process is a x86 process running on x64 OS instead; so it will return "false" for a x64 process on x64 OS.
Also, it doesn't handle errors correctly.

Here is a more correct method:

internal static class NativeMethods
{
    // see https://msdn.microsoft.com/en-us/library/windows/desktop/ms684139%28v=vs.85%29.aspx
    public static bool Is64Bit(Process process)
    {
        if (!Environment.Is64BitOperatingSystem)
            return false;
        // if this method is not available in your version of .NET, use GetNativeSystemInfo via P/Invoke instead

        bool isWow64;
        if (!IsWow64Process(process.Handle, out isWow64))
            throw new Win32Exception();
        return !isWow64;
    }

    [DllImport("kernel32.dll", SetLastError = true, CallingConvention = CallingConvention.Winapi)]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool IsWow64Process([In] IntPtr process, [Out] out bool wow64Process);
}

`Environment.GetEnvironmentVariable("PROCESSOR_ARCHITECTURE") == "x86"` will always return true for a 32bit process. Better to use `System.Environment.Is64BitOperatingSystem` if .NET4 is supported — Aizzat Suhardi, Oct 23 '17 at 03:23

score 11 · Answer 4 · answered Dec 23 '09 at 15:27

11

You can check the size of a pointer to determine if it's 32bits or 64bits.

int bits = IntPtr.Size * 8;
Console.WriteLine( "{0}-bit", bits );
Console.ReadLine();

answered Dec 23 '09 at 15:27

Darwyn

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At the time this answer was first posted it wasn't very clear, but the OP wanted to know how to query *another* process rather than the current process. – Harry Johnston Oct 19 '15 at 03:10

score 5 · Answer 5 · edited Aug 13 '13 at 15:12

5

[DllImport("kernel32.dll", SetLastError = true, CallingConvention = CallingConvention.Winapi)]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool IsWow64Process([In] IntPtr hProcess, [Out] out bool lpSystemInfo);

public static bool Is64Bit()
{
    bool retVal;

    IsWow64Process(Process.GetCurrentProcess().Handle, out retVal);

    return retVal;
}

edited Aug 13 '13 at 15:12

animuson

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answered Aug 13 '13 at 14:22

Praveen M B

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The OP specifically asked how to query *another* process, not the current process. – Harry Johnston Oct 19 '15 at 03:08
@HarryJohnston that code is valid with little change to get "other" process not current process, like `Process.GetProcessesByName("otherprocess.exe").First().Handle`, but using `IsWow64Process` from `kernel32` is an important part here! – psulek Jan 29 '23 at 12:19

score 2 · Answer 6 · answered May 09 '13 at 09:08

2

Here is the one line check.

bool is64Bit = IntPtr.Size == 8;

answered May 09 '13 at 09:08

Vikram Bose

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The OP specifically asked how to query *another* process, not the current process. – Harry Johnston Oct 19 '15 at 03:08

score 0 · Answer 7 · edited Jul 13 '12 at 18:40

0

I like to use this:

string e = Environment.Is64BitOperatingSystem

This way if I need to locate or verify a file I can easily write:

string e = Environment.Is64BitOperatingSystem

       // If 64 bit locate the 32 bit folder
       ? @"C:\Program Files (x86)\"

       // Else 32 bit
       : @"C:\Program Files\";

edited Jul 13 '12 at 18:40

Taryn

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answered Jul 13 '12 at 12:26

user1351333

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what about 32bit process in 64bit OS Machine ? – Kiquenet Aug 23 '12 at 12:30
4

Is it really so hard to use `Environment.GetFolderPath(Environment.SpecialFolder.ProgramFilesX86)` instead of hard-coding `C:\Program Files\`? – Luaan Oct 19 '15 at 11:12
4

Never hard-code "program files", because it's a localizable string. Αρχεία Εφαρμογών, Arquivos de Programas, etc. – stevieg Nov 11 '15 at 02:43

How to determine programmatically whether a particular process is 32-bit or 64-bit

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