So recently when playing a video game on my windows 10 pc my screen went black and the graphic card's fan speed instantly increased. After a few seconds my screen reappeared, my game stopped working and a popup message told me my graphics card has stopped working and sucessfully covered. I restarted my game to find out a few moments later that square pixels all over my screen appeared and shortly after my computer restarted. Going back into my video game the square pixels reappeared but quicker this time and my pc restarted. Upon start-up I went into my browser only and my screen went black, fans sped up. Then my screen reappeared and the pop up message stating my graphics card has recovered appeared. This happen immediately after multiple times till finally pixels appeared and my pc shut down. Sick and tired I left my pc. A few days later I tried to turn on my pc and random pixels appeared on start-up and are horizontal dashed lines now. My windows won't load and keeps restarting. A few different messages occurring are ; overclocking has failed, windows couldn't start up. I reset all bios setting and the overclocking has failed went away but windows wouldn't load up. I tried safe mode and that worked but that was it. It seems to me my graphics card is the issue as I changed it with an older one and windows successfully started up. I don't understand why this is happening and without using a new graphics card how I can fix my current one as I feel like it can still work but something is making it not work . I have a nvidia gtx 580 asus graphics card. 64bit windows 10. Asus rampage 2 motherboard .