There are 3 releases of every Windows XP version: launch retail (no service pack); integrated service pack 1 and integrated service pack 2. If you installed Service Pack 2 on a launch retail and then uninstalled it, this is the sort of thing you could expect to occur. We need to determine if you have any SP level by looking in system properties (click Start, Run and type sysdm.cpl). Under the System header it will tell you the following:

Microsoft Windows XP
Professional
Version 2002
[service pack installed, or blank if none]

I also asked for more information. Just your CPU and Windows version is not sufficient, please read this. Try to imagine what else might be important; thinks like the RAM, Hard Drives etc. If you've experienced problems with the system before etc. Read the link, think about it. Reading this might also help.

These rules don't just apply to itsallPC, but any help forum. The difference is, we try to be careful about understanding the problem and variables rather than just jumping to wild conclusions.