I had first ascribed this to AOL, but I uninstalled that weeks ago and still I have this problem: Every now and then I get a dialog box on the screen saying “Your hard drive [C:] is full,” and I have to digress and go to Disk Cleanup. What is it about a particular make of CPU–in my case Compaq Deskpro–that causes so many unwanted files to be downloaded from the Internet? (The cuplrit is usually Temporary Internet Files in the Windows folder.) Apparently these download automatically onto C: even when I don’t know it’s happening, anytime I’m on the Internet. What should I do about this? 
When you browse the internet you’re actually downloading html pages, and pictures to your computer. IE stores these in tempory internet files so the next time you need it, it can load it straight from the Hard Disk Drive which is many times faster than the net. You can override this behaviour by opening IE, clicking the “tools” menu, then internet options, then the advanced tab. near the bottom of this list of options you’ll see “Clear Tempory Internet Files Folder when closing browser” tick the box next to it and hit ok.
However if the small amount you’re getting of the net is filling your HDD to the brim, I might suggest getting a bigger HDD (they’re getting very cheap) or at least compressing some of the stuff on your HDD
You can restrict the size of your Temp Internet files cache. If you are using Internet Explorer, open it up, go to ‘tools’ then ‘internet options’ then ‘settings’ and look for the slider to set the size of your cache. I have mine set at 5 MB, but I think the default is much higher, like 120 MBs.
For what it’s worth, I use a program called WebWasher to remove all that crap. You can see info on it at www.webroot.com.
It’s shareware. I don’t remember the cost to register it.
Oops… let me correct that. It’s WindowWasher not Webwasher.