Is your machine running like a snail?
When was the last time Checkdisk was run? If it has been a while, go to My Computer, from the start button, and right click on the C drive.
Choose Properties, and click the "Check Now" under the "Error Checking" section of the Tools tab. Select both options (5 processes), click OK and reboot.
Let Checkdisk run through all 5 steps, and afterwards Windows will report that the disk is clean. I usually run this when the computer runs real slow.
Also, get a copy of "C-Cleaner". Download, and install. Run the app, and it will cleanup any temp files, and the "trashcan". Click on the registry option as well, and chose Analyze. Select Run, and choose "Fix All".
One last item, defrag the hard drive, and run Norton, or McAfee.
That should do it,