Let me explain. 100G is a lot of space.

If it says disk space is full it means you are using up the 100G of that space there. I doubt if you have 100G worth of software installed.

Instead what I think is happening is that your computer settings automatically save anything you are using in the C drive unless you tell it not to. So in this instance CCleaner may be handy to you.

So yes, whether you know it or not, then your stuff is being saved there. Open it up and remove anything you don't need from there. If you wish, move them to the other drives.

The best option is to take it to a good guy in town and they should be able to redistribute your hard drive space very quickly. I personally don't see why you should have 5 different hard drive partitions when you only have documents.

You can also disable hibernation,..if its on. Hibernation creates and allocates a huge system file that eats up space ..upto 1GB or your RAM size or more.
Reduce the size of the paging file also, and the size of your browsers cache.

http://www.opentutorial....bernation_in_windows_xp
Doing these things have their disadvantages of course

Download "Tree Size Viewer" from http://www.jam-software.com/freeware/ and use it to check which folder(s)/files in your C drive are taking up most of the space. Once you have that, you can decide to either delete or move them to the other drives.

Download "Tree size Viewer" from http://www.jam-software.com/freeware/ and use it to check the files/folders taking up most of the space in your C drive. With that information you can choose to delete or move the movable files/folders to the other drives.

Use a Linux based partition logic software and re-size your Disc. I would recommend 40Gb for your OS partition. Also as you install your programs, don't always install in the default location.