Almost, first uninstall everything you've added since you bought it in Control Panel/Add or Remove Programs.
Then clean up everything with diskcleaner, such as temp files and cookies. Then do a Repair install by clicking the below URL for instructions:
How to Perform a Repair Install with Windows XP http://www.michaelstevenstech.com/XPrepairinstall.htm
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.