Just off the top of my head, I suggest you remove the new memory and bootup the computer. If the computer behaves, then it's the new memory that's the problem. *** Another question: Just how did you downgrade your operating system? This problem might have been caused by that downgrade process. This is pretty confusing. I just checked the Microsoft Knowledge Base. They have absolutely no information on Memmap Vxd failure. They usually have just about everything listed there. Ron