Steam freezing pc when downloading games

So here's the situation I'm in. I'm trying to download Left 4 Dead 2, and whenever I do so, my computer literally freezes up and sometimes the download is on and off initially like it downloads at 5 mb/s, and then 0, etc and then it freezes up. At this point, I can't even ctrl + alt + delete or do anything except restarting my computer using the power button on my PC. At startup, steam usually resumes downloading games, and it would freeze up again, forcing me to restart. I know this is a problem with Left 4 Dead 2 because I booted windows back with safe mode and uninstalled the content which was already downloaded, and then my PC runs as it would normally. I'm able to download any other games no problem such as Deus Ex: Human Revolution, Killing Floor, and TF2, so it's not an early sign of my hard drive failing cause i literally just built this computer approximately 3 weeks or so ago.

Anyone know a solution to this problem or anyone who had a similar situation? I've tried and google fixes, but I can't find anything worthwhile that works.