I have Windows 8. The computer is largely crashing while trying to play a specific game (overwatch). I think it may be graphics card related (Radeon HD 4800). I have done the things that I was told to do to fix the problem, but it still persists. I would like to check the computer though. There seems to be a sluggishness to it, and its recently been starting up in some kind of 'error mode'. It will run through some kind of diagnostic. The game when it does crash totally locks up the computer. I dont have a firewall or anything so I assume I have at least some junk on it. Can anyone give me some advice on what to do? I am currently de-fragging the computer but that is about all I know how to do. What is a good anti-virus or malaware program? Also, how do I post a diagnostic for people to look at? Thank you!