How does one defrag their computer?

A friend sent me an e-mail, in it he asked:

How does one defrag their computer?

My reply back:

Well…

You remove the hard drive from the system and using an electron microscope you need to examine each individual hard drive cluster (there are 180,000 of them) and using a special de-fragment tool (looks like a kitchen knife but it’s not; it’s special) you have to re-organize the clusters in the proper order; which in and of itself is pretty easy. Just don’t put them in the wrong order otherwise you could cause the drive to go nuclear. Really pretty easy stuff. I do it all the time.

Or…

You could:

Start –> All Programs –> Accessories –> System Tools –> Disk Defragmenter –> window pops up make sure the C: drive is selected and click on Defragment.

Depending on how fragmented the drive is it could take a bit.

And, sorry I can’t resist:

Q: How does one defrag their computer?

A: You don’t, you defrag your hard drive.

Unless you mean “frag” in the sense of the video game or military use of the word, which is to “kill.” If that’s the case then when you ask “how does one defrag their computer?” you mean “how does one un-kill their computer?”

That, depends on how you killed it.