How to detect Windows 64-bit platform with .NET?

Question

In a .NET 2.0 C# application I use the following code to detect the operating system platform:

string os_platform = System.Environment.OSVersion.Platform.ToS         


        

Answer 1

Include the following code into a class in your project:

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

    public static int GetBit()
    {
        int MethodResult = "";
        try
        {
            int Architecture = 32;

            if ((Environment.OSVersion.Version.Major == 5 && Environment.OSVersion.Version.Minor >= 1) || Environment.OSVersion.Version.Major >= 6)
            {
                using (Process p = Process.GetCurrentProcess())
                {
                    bool Is64Bit;

                    if (IsWow64Process(p.Handle, out Is64Bit))
                    {
                        if (Is64Bit)
                        {
                            Architecture = 64;

                        }

                    }

                }

            }

            MethodResult = Architecture;

        }
        catch //(Exception ex)
        {
            //ex.HandleException();
        }
        return MethodResult;
    }

Use it like so:

string Architecture = "This is a " + GetBit() + "bit machine";

Answer 2

Given that the accepted answer is very complex. There are simpler ways. Mine is a variation of alexandrudicu's anaswer. Given that 64-bit windows install 32-bit applications in Program Files (x86) you can check if that folder exists, using environment variables (to make up for different localizations)

e.g.

private bool Is64BitSystem
{
   get
   {
      return Directory.Exists(Environment.ExpandEnvironmentVariables(@"%PROGRAMFILES(X86)%"));
   }
}

This for me is faster and simpler. Given that I also wish to access a specific path under that folder based on OS version.

Answer 3

Use these two environment variables (pseudo code):

if (PROCESSOR_ARCHITECTURE = x86 &&
    isDefined(PROCESSOR_ARCHITEW6432) &&
    PROCESSOR_ARCHITEW6432 = AMD64) {

    //64 bit OS
}
else
    if (PROCESSOR_ARCHITECTURE = AMD64) {
        //64 bit OS
    }
    else
        if (PROCESSOR_ARCHITECTURE = x86) {
            //32 bit OS
        }

Refer to the blog post HOWTO: Detect Process Bitness.

Answer 4

I used this check with success on many operating systems:

private bool Is64BitSystem
{
   get
   {
      return Directory.Exists(Environment.ExpandEnvironmentVariables(@"%windir%\SysWOW64"));
   }
}

This folder is always named "SysWOW64", no matter of the language of the operating system. This works for .NET Framework 1.1 or above.

Answer 5

I'm using the followin code. Note: It's made for an AnyCPU project.

    public static bool Is32bitProcess(Process proc) {
        if (!IsThis64bitProcess()) return true; // We're in 32-bit mode, so all are 32-bit.

        foreach (ProcessModule module in proc.Modules) {
            try {
                string fname = Path.GetFileName(module.FileName).ToLowerInvariant();
                if (fname.Contains("wow64")) {
                    return true;
                }
            } catch {
                // What on earth is going on here?
            }
        }
        return false;
    }

    public static bool Is64bitProcess(Process proc) {
        return !Is32bitProcess(proc);
    }

    public static bool IsThis64bitProcess() {
        return (IntPtr.Size == 8);
    }

Answer 6

Just see if the "C:\Program Files (x86)" exists. If not, then you are on a 32 bit OS. If it does, then the OS is 64 bit (Windows Vista or Windows 7). It seems simple enough...