My laptop bluescreened and then restarted

Hello,
I just started up my computer and after a few minutes, connected it to the internet and tried going on firefox and MSN Messenger. I don't know what happened on screen because I was looking away, but something flashed on the screen that caught my attention and I found that my laptop had blue screened. The words on the screen went by really fast, but I caught something about a 'driver', and then my laptop restarted itself. When it restarted, it seemed fine. I chose to reboot normally and the login page was normal. I logged in and the screen was completely black with the arrow cursor in the middle. After a few mintues I could move the cursor, but the screen stayed black until I pressed ctrl+alt+delete.

I am really freaking out here, I can't afford a new computer and I don't know if the blue screen will happen again. Any advice would be great.