You don't say anything about your PC which is unhelpful. Nor do you give any hints as to when and doing what it runs slow.
However if it is running WinXP SP2 then it needs at least 512MBytes of RAM as a start. Second, defrag your hard disk. Finally get rid of any programs that you no longer use using the built-in Utility (don't just delete the code).
t
December 2007