First things firsts welcome to seven forums, sorry your computer not running good but with the folk around here I'm sure they will be able to sort it.
I'm unfamiliar with that card/chip(gpu) but after a brief search I am of the opinion that your computer should be able to run win 7 with no probs.
Who installed windows 7? Was it a clean install or an upgrade? Has it always run like this?
What programmes are enabled from the start because 5 mins is it touch too long for a boot up.