还可以检查PROCESSOR_ARCHITECTURE环境变量。

它要么不存在，要么在32位Windows上被设置为“x86”。

private int GetOSArchitecture()
{
    string pa = 
        Environment.GetEnvironmentVariable("PROCESSOR_ARCHITECTURE");
    return ((String.IsNullOrEmpty(pa) || 
             String.Compare(pa, 0, "x86", 0, 3, true) == 0) ? 32 : 64);
}

我正在使用以下代码。注意:它是为AnyCPU项目制作的。

    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);
    }

下面是c#中使用DllImport的直接方法。

[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; 
} 

一切都很好，但这也应该在env中工作:

PROCESSOR_ARCHITECTURE=x86

..

PROCESSOR_ARCHITECTURE=AMD64

可能太简单了;-)

只要看看“C:\Program Files (x86)”是否存在。如果不是，那么你使用的是32位操作系统。如果是这样，那么操作系统是64位(Windows Vista或Windows 7)。

下面是Windows管理规范(WMI)方法:

string _osVersion = "";
string _osServicePack = "";
string _osArchitecture = "";

ManagementObjectSearcher searcher = new ManagementObjectSearcher("select * from Win32_OperatingSystem");
ManagementObjectCollection collection = searcher.Get();

foreach (ManagementObject mbo in collection)
{
    _osVersion = mbo.GetPropertyValue("Caption").ToString();
    _osServicePack = string.Format("{0}.{1}", mbo.GetPropertyValue("ServicePackMajorVersion").ToString(), mbo.GetPropertyValue("ServicePackMinorVersion").ToString());

    try
    {
        _osArchitecture = mbo.GetPropertyValue("OSArchitecture").ToString();
    }
    catch
    {
        // OSArchitecture only supported on Windows 7/Windows Server 2008
    }
}

Console.WriteLine("osVersion     : " + _osVersion);
Console.WriteLine("osServicePack : " + _osServicePack);
Console.WriteLine("osArchitecture: " + _osArchitecture);

/////////////////////////////////////////
// Test on Windows 7 64-bit
//
// osVersion     : Microsoft Windows 7 Professional
// osservicePack : 1.0
// osArchitecture: 64-bit

/////////////////////////////////////////
// Test on Windows Server 2008 64-bit
//    --The extra r's come from the registered trademark
//
// osVersion     : Microsoftr Windows Serverr 2008 Standard
// osServicePack : 1.0
// osArchitecture: 64-bit

/////////////////////////////////////////
// Test on Windows Server 2003 32-bit
//    --OSArchitecture property not supported on W2K3
//
// osVersion     : Microsoft(R) Windows(R) Server 2003, Standard Edition
// osServicePack : 2.0
// osArchitecture: