OK, I know this has been discussed before.  I need to detect when I am
running on 64 bit windows, and write a specific key to the 32 bit node
for VS 2005 to load my plugin (I am 64 bit, it is 32 bit).

ManagementObjectSearcher mso = new ManagementObjectSearcher("SELECT *
FROM Win32_OperatingSystem"); //Win32_ComputerSystem");
ManagementObjectCollection qc =  mso.Get();

Console.WriteLine("OSArchitecture: " +
mo["OSArchitecture"].ToString());

That is the C# code to get the OSArchitecture from the WMI interface.

My question is, why does it blow up on my Windows XP 64 bit install?
It appears to work fine under 64 bit Vista - I get a response of
either 32 bit or 64 bit as I would expect.