Mid-2011 MacBook Pro freezes and beeps 3 times

I am trying to figure out why my girlfriend's 2011 MacBook Pro 13-inch computer running Mac OS X 10.6.8 keeps freezing and beeping 3-times, rendering the machine virtually useless right now.

It started a week or two ago. She was using it and then it froze and started beeping continuously in groups of 3 beeps. The only way to stop it was to push the power button down to shut if off. I've restarted it multiple times but every time it will freeze and start beeping. Usually it happens after she logs into the computer with her user/password.

So far I've tried taking out the ram and then replacing it to see if perhaps it was loose. I also have been trying to play around with it a bit and tried starting it in safe boot mode -- but it still ended up freezing and beeping.

The most recent time I tried starting it up, this message popped up (and to my knowledge, this is the first time this has happened):

I also saw somewhere that it could be related to Google Drive, but I haven't been able to even check into it because I can't get the computer to stay stable long enough to uninstall it.

Anyone have any suggestions?