Defragmenting....

So, I havn't defragmented in a long time, mostly because the drive was too full, and after moving and deleting a bunch of files, this is what my drive turned out to look like:

http://www.coreno.info/fragmented/

Here is a description of what fragmentation and defragmentation is:
Take a look a the "drive map". That's literally a map of the drive, and where data is on it.

When files are saved on the harddrive, they are saved in the first available free space. Say you save 2 files, the first file is 10Kb, and the 2nd one is 100kb. Then you delete the first file... that leaves 10kb of free space in front of the 2nd file. If you then save a 50kb file, the first 10kb of that file will be saved in the 10kb of free space in front of the 2nd file, and the rest is saved after it. Now that file is fragmented, because it's saved in two physical locations on the disk. File 2, is still contigious, and not fragmented.

When you defragment, it rearranges the files so that they are all contigious. So, in this case, it would probably move File 2 somewhere else, re-save File 3 so it's all together at the beginning.

How to do it
1. Open "My Computer", right click your harddrive, and click properties.
2. Click the tools tab. Click Defragment Now.
3. Select the drive you wish to defragment, then click Defragment at the bottom.

Note: the program I used is not the one in Windows XP, I used Executive Software Diskkeeper.