I am trying to figure out if there is a location in WMI that will return the OS Architecture (i.e. 32-bit or 64-bit) that will work across \"all\" versions of Windows. I though
This isn't exactly what you asked for, but I just used this in a WMI query (Group Policy Preference targeting) and it appears to work thus far:
SELECT * FROM Win32_ComputerSystem WHERE SystemType="x64-based pc"