Defragmenting your hard disk is one of the best things you can do to speed up your Windows computer. How? Think of your hard drive like a file cabinet. If you're like most people, you've got your papers stored in alphabetized folders so you can find things easily.
Imagine, though, if someone took the labels off the folders, switched the locations of all the folders, and moved documents into and out of folders at random. It would take you a lot longer to find anything, since you wouldn't know where your documents were. That's sort of what happens when your hard drive gets fragmented: it takes the computer much more time to find files that are scattered here, there and everywhere. Defragmenting your drive restores order to that chaos, and speeds up your computer -- sometimes a lot.
Defragmentation is available in Windows XP and Windows Vista, although there are some differences between the two. The most important is that Vista allowed scheduling of defragmentation: you could set it to defrag your hard drive every Tuesday at 3 a.m. if you wanted. In XP, you had to defrag manually.
It's just as important to defrag a Windows 7 computer on a regular basis, but there are some new options, and a new look. To get to the defragger, click on the Start button, and type in "disk defragmenter" in the search window at the bottom. "Disk Defragmenter" should appear at the top of the search results, as shown above.