No not needed but you should defragment your hard drive also download and install CCleaner and run it it will delete all your temp files, cookies (if you do online baking or play games goto options and cookies and move those cookies to the keep side)and will remove any left over files not needed. After finished CCleaner look and see if you have to defrag your hardrive again. If you clean your registry make sure you say yes to back up your registry and remeber where the file is saved.
John D
March 2008