He did mention being unable to play GTA:SA and Second Sight.
I hope you have been using original games because pirated games with their cracks can lead to serious trobles with the OS. Particularly so with Second Sight as it's a game using Starforce Protection which is very, very hard to crack. Even the original games saddles you with the burden of a very complicated authentication system.
Also check if their is a hardware conflict. Maybe something that you recently installed that might be the cause of the problem.
It would also be helpful if you post the exact error message that you get in the Blue Screen a.k.a. BSOD or Blue Screen Of Death. Then our gurus here can help you pinpoint the exact problem.