When a Windows XP user asks how to fix a problem they've recently started having with their PC my first response is to use System Restore to roll it back to a point just before the problem started. I've found the majority either don't know how to use it, don't know what it does, turned it off because it uses too much disk space and virtually all say that Microsoft's Help file is not very helpful to which I'd agree. However it is one of the best utilities Microsoft has ever written and works extremely well.
Using System Restore is a straightforward, step by step help guide explaining how to use it with a minimal amount of disk space, what it does and how it works. System Restore can return your system to an earlier state if problems are caused by a program you installed, malicious web sites, recovery of deleted files even after you've emptied the Recycle Bin, a corrupted Registry as well as many other common problems. By using it regularly you'll always be able to fix a problem in minutes. The article is available for viewing online and as a downloadable Help file (.chm) for installation on your PC.