Aspire 5740G fan not working after fresh Windows install

Hey guys. I recently decided that I want to format my laptop to get rid of all the useless junk I'd accumulated, and instead of using the factory restore disk I opted to do a completely fresh install of windows 7 and install the drivers myself.

That was all fine but now that I've done it I've noticed a significant drop in my fans effiency. I loaded up skyrim and within 20 minutes it shut itself down due to overheating. Before the install this wasn't a problem.

This isn't actually the first time this has happened either. The last time it was still under warranty and I formatted it in favor of a clean install. Doing anything more intensive than web browsing would cause it to over heat and shutdown. This was while my machine was still under warrenty so I sent it away and got it back relatively quickly with a notice saying that it was a software issue and they had restored it to factory defaults to fix it.

With this in mind I'm fairly certain that resetting it to factory defaults would fix my issue. I'd rather not if I can avoid it as I just finished installing all the updates, anti virus software etc. Is there an acer driver or program that I am missing?

I installed the epower manager that acer says goes with my machine, but it doesn't appear to have done anything except restore the beeping noise whenever it is plugged in or unplugged.