Computer - Blue Screen

My computer has screwed up twice in the past 3 or 4 days. It gets a bunch of lines across the screen starts making weird noises then gets a blue screen. When I shut it down and turn it back on everything works fine.

 

Done all Windows critical updates?
Suffered from any viruses recently?
Scanned for viruses?
Have you made any changes to your PC that started these blue screens?

At the end of the day, your OS could just be failing. I would start backing up everything you want to keep and do a re-format.

 

Check windows logfile > system logs

You'll probably get an error code there or something else useful.
Most of the time it has to do with the RAM memory btw, or the videocard sometimes.