How do I fix this?

when i go to download updates from MS a message appears that my PC is in an unstable conditition and that I should go to remove programmes and uninstall XP. (why?) I tried this but was unable to run my PC properly so I restored it back.
Is there a programme that scans my PC to tell me what updates I need and installs it automatically without the message appearing..?
Thanks a mil!!!

Can you provide a more detailed description of what exactly happened/is happening including the exact text of any error messages that appear please? Thanks.

Sounds like you need to as a first step.

I think it means that recent updates were not properly installed - probably service pack 2. and you have to uninstall it and then reinstall.