I'll be honest with you, you have to be pretty dumb to let this happen. There are very few sites out there that can install viruses into your machine, and you actually downloading a program and installing it is another story. I would guess this is #2. You're either using filesharing programs to illegally download your music, movies & games, or you just happened to download the wrong software.
The bluescreen is pretty common when particular software jumbles up your system registry, among other things. You're ****ed, unless you get a pro to come fiddle with it.