I have a simple question: I currently have the Catalyst 5.5 driver for my video card, but I would like to get the 5.6 version. If I download and install it, will it just overwrite the old version?
It will overwrite and 99.9% of the time it will be correctly. It's a bigger problem if you're switching from an nvidia card to an ati, because nvidia doesn't completely erase all of their stuff. Clearly that's not you, though.