BSOD before virus scan can complete - In fear for my computer!

I am...young and very noobish at computers. I have a major problem, and I need to set up the premise, so please bear with me!

I share a desktop with the family, and we've had it for almost three years without any problem. But, just a few weeks ago we were infected with Spyware Protect 2009 (which I read was from the Conficker worm...?). The Verizon virus scan didn't work, so I downloaded Malwarebytes and that seemed to work quite well.

Then, I was getting warnings that I was low on disk space (below 200 MB). So I did a disk cleanup and deleted some programs, but the free space was unchanged. Local Drive :C supposedly had over 75,000,000 bytes used with only <1 GB free...is this possible? The only major applications we have are The Sims, few smaller programs like Corel Painter and GIMP, and of course the Internet, which I delete cookies and all that from the history. It doesn't seem right.

But then it got bad. Just today, the computer seems to have been infected with "Advanced Virus Remover ", which seems like a scam similar to the previous. This has many more fake warnings and windows to click out of. When I try to run a virus scan, it'll start and then I'll get the Blue Screen of Death, causing me to manually restart the system. Also, any Internet browsing causes it to crash in the same way (I'm using an old laptop now). Is it crashing because these things fill up the harddrive?

So, I'm pretty immobilized with these factors. I can't seem to do anything! Why is my harddrive so full? Are there any ways other than deleting files and history to free it? And how do I get rid of this virus when I can't keep the computer open for more than five minutes (when scan is running)? I really fear this could be the end for it. If anyone could help, it would be greatly appreciated. Thanks for reading.

 

Oh, whoops! Will do. Thanks!