考虑到公认的答案非常复杂。还有更简单的方法。我的答案是亚历山德鲁库的。 考虑到64位windows在Program Files (x86)中安装32位应用程序，您可以使用环境变量检查该文件夹是否存在(以弥补不同的本地化)

如。

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

这对我来说更快更简单。鉴于我也希望访问基于OS版本的文件夹下的特定路径。

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;-)

使用以下两个环境变量(伪代码):

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
        }

请参阅博客文章HOWTO:检测进程bit。

我发现这是检查系统平台和流程的最佳方法:

bool 64BitSystem = Environment.Is64BitOperatingSystem;
bool 64BitProcess = Environment.Is64BitProcess;

第一个属性对于64位系统返回true，对于32位系统返回false。 第二个属性对于64位进程返回true，对于32位进程返回false。

需要这两个属性是因为您可以在64位系统上运行32位进程，因此需要检查系统和进程。

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; 
} 

这是一个基于微软http://1code.codeplex.com/SourceControl/changeset/view/39074#842775代码的解决方案。它使用扩展方法方便代码重用。

下面是一些可能的用法:

bool bIs64BitOS = System.Environment.OSVersion.IsWin64BitOS();

bool bIs64BitProc = System.Diagnostics.Process.GetCurrentProcess().Is64BitProc();

//Hosts the extension methods  
public static class OSHelperTools  
{  
    /// <summary>     
    /// The function determines whether the current operating system is a      
    /// 64-bit operating system.     
    /// </summary>     
    /// <returns>     
    /// The function returns true if the operating system is 64-bit;      
    /// otherwise, it returns false.     
    /// </returns>    
    public static bool IsWin64BitOS(this OperatingSystem os)  
    {  
        if (IntPtr.Size == 8)  
        // 64-bit programs run only on Win64           
            return true;   
        else// 32-bit programs run on both 32-bit and 64-bit Windows     
        {   // Detect whether the current process is a 32-bit process                
            // running on a 64-bit system.               
            return Process.GetCurrentProcess().Is64BitProc();  
        }  
    }  

    /// <summary>  
    /// Checks if the process is 64 bit  
    /// </summary>  
    /// <param name="os"></param>  
    /// <returns>  
    /// The function returns true if the process is 64-bit;        
    /// otherwise, it returns false.  
    /// </returns>    
    public static bool Is64BitProc(this System.Diagnostics.Process p)  
    {  
        // 32-bit programs run on both 32-bit and 64-bit Windows           
        // Detect whether the current process is a 32-bit process                
        // running on a 64-bit system.               
        bool result;  
        return ((DoesWin32MethodExist("kernel32.dll", "IsWow64Process") && IsWow64Process(p.Handle, out result)) && result);  
    }  

    /// <summary>     
    /// The function determins whether a method exists in the export      
    /// table of a certain module.     
    /// </summary>     
    /// <param name="moduleName">The name of the module</param>     
    /// <param name="methodName">The name of the method</param>     
    /// <returns>     
    /// The function returns true if the method specified by methodName      
    /// exists in the export table of the module specified by moduleName.     
    /// </returns>       
    static bool DoesWin32MethodExist(string moduleName, string methodName)  
    {  
        IntPtr moduleHandle = GetModuleHandle(moduleName);  
        if (moduleHandle == IntPtr.Zero)  
            return false;    
        return (GetProcAddress(moduleHandle, methodName) != IntPtr.Zero);   
    }  
    [DllImport("kernel32.dll")]  
    static extern IntPtr GetCurrentProcess();  

    [DllImport("kernel32.dll", CharSet = CharSet.Auto)]  
    static extern IntPtr GetModuleHandle(string moduleName);  

    [DllImport("kernel32", CharSet = CharSet.Auto, SetLastError = true)]  
    static extern IntPtr GetProcAddress(IntPtr hModule, [MarshalAs(UnmanagedType.LPStr)]string procName);  

    [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]  
    [return: MarshalAs(UnmanagedType.Bool)]  
    static extern bool IsWow64Process(IntPtr hProcess, out bool wow64Process);  
}