Need help with Dota causing my computer to freeze.

Hey, I found this site a while back; and since I'm getting a bit tired of playing pugs where-in my teams are often horrendously incompetent, I decided on join to look for a team of competitive players.

However, before I can join a team there is an issue I need to address. You see, every once in a while I'll be playing a match, and all of the sudden my computer will just completely freeze. Everything on the screen stops entirely, the sounds stops, the screen locks, I can't move the cursor, and I can't minimize/ctrl-shift/etc. I have to do a complete reset with my computer and I can never re-join the game in time.

I really need to fix this issue, but from the other trouble-shooting threads I've read, it seems like people are experiencing something a bit different from this. For anyone interested, I'm running Windows 7 64-bit, and my computer specs far exceed the required presets to run the game.

Thanks in advance for any advice.