Trixton

I have a strange problem on my mom's computer at work. She is using a Sony VAIO with P4 1.8Ghz processor, 512MB RAM, with 2 hard drive partitions. The C drive partition is 16GBs total and the D drive is 60GBs total. Now, my problem is that she does not manage a computer well and the C drive has inevitably filled up quickly. There are a couple of major problems that I cannot find the root of the problem for:

1) I moved all the documents over from the C drive to the D drive to free up space, but after this was done, there remained multiple gigs of space used in her C drive documents folder. I went into the folders with the most space used and looked at the files and there wasn't a single folder with more than a few MBs in it. So i ran the command prompt and went into the same folder so that I could see all the files with the different properties attached, but there was the same problem. I could not find these files that were taking up gigs of space. This is in multiple folders under her "My Documents" folder on the C drive, not just one. I have no idea what could be causing this.

2) On the C drive a few days ago, there was 300MB of storage left, and today when I first walked in the door, there was 133MB left, and right now there is 123MB left and I haven't downloaded anything. I don't know if this is being caused by some sort of virus or whatever.

This is all really confusing because I don't do troubleshooting well and this is not my computer, so any help on this matter would be greatly appreciated. Please let me know if there is any information that I have left out. Thanks.