System Restore will solve some of the problem. XP SP2 has more background services and may be crippling older machines. Try Window Key/Pause Break -> performance options, Set Visual effects to best performance, advanced tab--> virtual memory to a separate disk drive preferably, or just increase the size by one increament of your total memory. Terminate unused services. Adjust down virus scanner settings to when writing to disk, especially if you are using Macafee.