Quote from TSSOX:
Other than formating HDD's and reinstalling Win, what's the next best way to clean the pc?
Quote from kiwi_trader:
Get yourself a copy of Acronis True Image and do a clean install including the major programs you need. Then save the image - you can restore this image later in 15 minutes.
Why? Because windows XP SP3 RC is out and your system will run faster with it! So its worth doing a clean install of SP2+ your software and saving the image and then adding SP3. In a few months the final SP3 will be available and you can save the SP3 version.

Quote from gnome:
You can run "cleanup" and "repair" programs.. and they are usually effective to a degree.
However, XP still needs a fresh install periodically to clean up additional schmutz and to eliminate errors which Windows has accumulated.
Quote from jhithers:
When you do a fresh install of XP, do you have to re-install all of your drivers?
Not open source? Goes in the trash.Quote from 9999:
Of course.
And if you do a fresh install, I strongly recommend this software:
http://www.nliteos.com/
It lets you configure the install process in many ways.