upgrade to ssd for 40 bucks. no joke.

[Failhorse]

OK this thing isn't the top of the line, and I believe is outdated and discontinued.
But it's still an SSD and it's priced cheap.
http://www.tigerdirect.com/applications ... bBhlNLlLMQ

AT 80GB, I'd leave the OS on your current drive and just move over your games folder (steam and whatever else.)