tangor - 12:24 pm on Apr 29, 2009 (gmt 0)

If you don't have any serious data on the system your most cost effective route would be to format and reinstall. Home is not as robust as Pro, but does run pretty good as a clean system.

If you play a lot of different games it is possible some critical files have been modified or corrupted over time.

I'd avoid Vista.

Hang on for a bit, Win7 will most likely appear this year. By most reports it is a better user experience than Vista...and will include an XP mode which means your existing apps will continue to work.