How to fix my computer?

I played a game couple of hours and kept freezing with a blur on the screen, so I had to reset it several of times and now when i start it again it keep freezing during the start up of the windows. Now I got the blue screen of death. I have no idea what to do now. What i did to try to ease the problem was to use an air compressed can and just took the dust. I didnt think it help. Please help me.