BleepingComputer.com: Pc Performance.

I have access to my son's PC when I visit him. I don't know all the specification but I do know that the PC has 2.4 gb pent4 processor. The machine is agonisingly slow!!! Six minutes minimum from boot-up to usability!! When an application is closed, it scrolls down the screen, and takes a good 1.5 seconds to disappear. I have used registry cure spyware cures anti virus progs - all to no avail. Now as my son is entering his third year at University, an efficient PC is essential. HELP.

Make sure with windows xp that it has at least 512 megs of ram, now seriously consider doing a clean install, then remove everything that he won't use in the way of cruddy programs, defrag the computer, apply any service packs and updates.
Defrag again, check the guides for improving performance, and tell him to maintain the computer.

I would echo everything DaChew said but specs would be usefull,. Possibly your son's Pc is running low on hard drive space thus one of the reasons why the machine is slowing down. There could be others but if poss post us the spec.