Windows: Cannot add Active Directory Users and Computers snap-in in Windows XP 64 bit

AD Users and Computers, and a few other administrative snap-in’s are 32 bit components. To add those snap-in’s to your mmc you will have to run mmc with /32 switch.

In order to be able to save your console for future use and be able to access all 32 and 64 bit components, you need to save two copies. Run an instance using mmc.exe and the other mmc.exe /32, then save both with different names you can recognize.