Virus that takes up almost more than half of computer?

Ive had this problem for a while now... I have a Dell Inspiron 1100 and it has apparently 106 gigs of space and right now I only have 47 gigs of free space and I know Im not using up more than half the laptops total space. Ive maybe got 10-25 gigs of space that I know Im using up of videos, music, pics and Call of Duty 4....
I used to burn DVDs a lot a while ago using Nero and I thought I had checked everywhere possible to see if that program left any remnants of my burned dvds on my computer... I was also told it could be a virus that just keeps copying itself and can take up a good section of your space on your drive... does anyone have any suggestions on how to go about trying to figure out how or where to find out where all this space is being taken up?

 

http://lifehacker.com/software/disk-space/geek-to-live--visualize-your-hard-drive-usage-219058.php

 

hey Ill give the WinDirStat a try, its working on it right now, hopefully itll help me find some old files or something I must of forgotten about, thanks
anything else that I might wanna give a try at?

Edit:
It came up that I had a lot of files stored up in the MSOCache folder, and the folder names are just a bunch of random numbers... are they ok to delete or should I not?

 

http://www.theeldergeek.com/msocache_folder.htm

 

Know what probably takes up more space than you would ever think it would? Your Temporary Internet Files folder(s). I was in the same boat as you a few months ago, and I realized I hadn't cleaned out my temp files in...well, pretty much ever. Make sure you can view hidden files/folders (In any directory, go to Tools > Folder Options > View tab > Show hidden files and folders), then this should be the path you want to follow: C(or whatever your main drive is):\Documents and Settings > (user name) > Local Settings. From there, clear out both your Temp and Temporary Internet Files folders (don't delete them, but empty them). Repeat for all user accounts if there are any others. I warn that doing so WILL delete any stored passwords/login information on websites, but with the space it can free up (around 20 gigs the first time I did it) is well worth it.

 

yeah I think a guy at my college may of did that to my computer earlier this year, ill try it myself tho and see if it helps, thanks

 

Do you use wireless internet? There's a file that accumulates a large amount of data and just grows bigger, but it depends what driver you have.

 

yep I do... i seem to be having alot of problems with this laptop latlely

 

See if you can download an update for the driver. The driver may be infected with a Trojan collecting information about your computer. So if you update the driver, the problem should not longer exist.