Well you could be visiting web sites that creating cached files, depends on what web sites you visit regularly.
Do you play either on-line games or installed games? Ones that start you off where you were in the game last save a file to your hard drive.
It is not easy to pin-point exactly what program has the most disk space used, that I am aware of, but you can use two disk utilities that are usually used to defrag hard drives.
Using either Defraggler or Auslogics Disk Defrag, you can click on the blocks to see what files each block contains to get a basic idea what consumes most of your hard drive.
Heres the links to both programs which are freeware.
Defraggler. (note this is the download link) http://www.piriform.com/defraggler/download/standard
Auslogics Disk defrag. http://download.cnet.com/Auslogics-Disk-De...&tag=button
Edited by MrBruce1959, 21 May 2010 - 09:45 PM.