Alright, here we go. I recently sold my computer to my friend and when it got it the hard drive was busted. Okay, so he fixed that. Now, when he booted on the OS (Which is the same OS I shipped him, BTW. They just restored the OS and some files onto a new HDD.) and launched Team Fortress 2 he noticed the screen was kind of.. artefacting, and not to mention the bad FPS. Later the computer crashed and then began just popping up black screens.
So when he contacted me my first assumption was that the drivers were corrupted due to the new HDD. So we installed the correct programs and tried to uninstall the old ones and install the new one. He successfully uninstalled the old ones and tried installing the new ones it just froze and black screen'd. One time the PC did restart after like 20 minutes of being black but the drivers never installed.
So what could be the problem? I've tried looking this problem up with no resolve. Any help would be greatly appreciated. If you have any questions don't hesitate to ask me. Thank you.