Swap out video cards
Like to add, get another video card to help resolve this. Don't do any OS installs or swap OS, until you have the video problem resolved, otherwise, you'll be complicating it all.
If you have a decent PC case, be sure it's cooling well. Video cards are a enmorous source of heat and they are known to destruct due to poor manufacturing or comprised cooling, so pay attention to all this. Alas, a new video card should be well supported a great PSU as well for a good overall match. Heat always finds the weakest link in a PC, so cooling is important.