Most computers have the ability to restore Windows XP to the point where it was working properly. You would go to all programs, then accessories, then system tools. From there select system restore. It will show you a calendar with restore points marked for you. Select a date on which you are sure your PC was working corectly. Follow the prompts and the system will correct itself. If after using system restore you feel your PC is still not working up to par you can undo that system restore and run it again with a earlier date selected as your restore point.