When you start the Disk Cleanup, it will scan your computer for computer trash. Depending on the size of your hard drive and the amount of data that you have accumulated on your computer, this can take a little while. When Dick Cleanup finishes its scan it will give you a list of items that are potential "cleanup items". It will list things like Downloaded Program Files, Temporary Internet Files, and other Temporary Files. It will also give you the option of emptying the Recycle Bin and Compressing Old files. You simply put a check mark in front of each item that you want the Disk Cleanup to delete or each action that you want it to perform. Don't worry about deleting these files, you don't need to keep them around.

For a more thorough cleaning, you can click on the More Options tab in the Disk Cleanup window. This will give you the option of removing Windows components, installed programs, and System Restore points. You should be careful when deleting these items, making sure you won't need them anymore.

For more detailed information on cleaning up your computer, read my How to Clean the Hard Disk article in the Tutorial Section.