Mass Effect (TM) 3 stops working (pc)

From the looks of it you're playing on a notebook? Are you by any chance playing on battery, maybe some power-save function kicking in - you could try to set the energy settings for "high performance" and always play while plugged in.

Or maybe a new graphics card driver can solve your issues since it seems like you're having a rather old one. Can you right-click on the desktop and look for the AMD-settings? Under "information/software" there should be a screen like this. The latest release driver version is Catalyst 13.1 - you can try to download the new version from the AMD homepage here.  Most notebooks, like Acer or HP need for the ATI driver to be properly installed to be set to "fixed graphics" in the BIOS. Here is a tutorial for HP, It should be pretty similar for every other Notebook-brand. Just don't download the AMD drivers there, since those are rather old as well and stick with the ones from AMD themselves. But certain Notebook manufacturers don't allow for vanilla AMD drivers to be installed, so you might want to check the homepage of your notebook manufaturer for updated drivers (although these are most liekely not the latest ones) or try your luck with "unofficial" ones like here but use those at your own risk as they are usually modified in order to be recognised.