A few days ago, I installed WWE 2k19 on my computer. It was a little slow. It had a few lag spikes. So I checked task manager and saw that my CPU usage was nearing 100%, so I went on Msconfig and changed the cores from 1 to 4. After a while, I eventually restarted my computer. Everything looked normal; the HP logo, the windows 7 boot screen.... but one problem. When it should have went to the login screen, instead I saw a flash of a blue screen, and then my PC restarted. To see the actual issue, I disabled restart on system failure. The error code was: BAD_SYSTEM_CONFIG_INFO. Now, that's not the reason I'm here. The reason I'm here is because, whenever I try to do a startup repair (By selecting repair your computer by pressing f8 at the startup screen), instead of it opening startup repair, the screen goes black for about 2 minutes, and then the PC turns off. Safe mode, last known good config, disable blah blah blah, everything, will not work. Can someone help me fix this? Or at least tell me how I can uninstall windows 7 and install windows 10? Because I have changed the cores before, and every time I've done it (Which was done on windows 10) it worked. I just need help.