I pinpointed the problem. I have the WAMP server up. I disabled everything (zone alarm pro, nod 32). Everytime I type "localhost" on the web browser it restarts.
But what is puzzling is last night it restarted in the middle of the night too and woke me up at 3am in the morning. So it can't be just the "localhost" with Wamp Server up. I'll try what you said.