Actually depends on what defragment tool he is using. If its the windows one, he'll still have fragmented system files all over the place.
I recommend
defraggler, gets rid of all fragmented files including system ones.
Alternatively you can just leave your computer in screensaver mode all night while you're asleep. Windows automatically defragments with its "spare time" including system files!
In modern warfare 2, its always funny to watch a host take a good 15-20 seconds to load a map that takes me 2. And then saying "you should defragment" and they go "what is that?"
/My helpful advice when no body asked for it
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