public static int GetOSBit()
{
 try
 {
  string addressWidth = String.Empty;
  ConnectionOptions mConnOption = new ConnectionOptions();
  ManagementScope mMs = new ManagementScope(@"\\localhost", mConnOption);
  ObjectQuery mQuery = new ObjectQuery("select AddressWidth from Win32_Processor");
  ManagementObjectSearcher mSearcher = new ManagementObjectSearcher(mMs, mQuery);
  ManagementObjectCollection mObjectCollection = mSearcher.Get();
  foreach (ManagementObject mObject in mObjectCollection)
  {
   addressWidth = mObject["AddressWidth"].ToString();
  }
  return Int32.Parse(addressWidth);
 }
 catch (Exception ex)
 {
  return 32;
 }
}

[DllImport("kernel32.dll", SetLastError = true, CallingConvention = CallingConvention.Winapi)] 
[return: MarshalAs(UnmanagedType.Bool)] 
public static extern bool IsWow64Process([In] IntPtr hProcess, [Out] out bool lpSystemInfo); 
private static bool Is64Bit() 
{
bool retVal; 
IsWow64Process( Process.GetCurrentProcess().Handle, out retVal); 
return retVal; 
}