[wombie]

i'd definatly recommend a format, it will seem like a new machine. just be sure you have a copy of windows and drivers for your audio, LAN and graphics drivers before you do so. If you forget any other drivers at least you can get on the internet to get them this way. Also be sure to back up yours stuff. don't forget things like your fonts and your internet bookmarks, maybe your outlook mailboxes too if you use that.

After the format i would highly reccomend partitioning your harddrive and installing your programs on a seperate partition (the d:/ for example) this way you can use an imaging program such as norton ghost to create an image of your c:/ which you can back up to a DVD. this way if anything goes wrong in the future you can just reload the backed up ghost file and you'll be back to a fresh format in a few minutes.

hope this helps