So I got an issue for a few days from which I bang my head in the wall. As I try to start windows 8.1, the windows logo pops out with the loading circles for a few seconds then everything goes black screen and after 3-4 mins it says "your pc ran into a problem" then restarts and goes to automatic repair infinite loop. The worst part here is that the pc has an issue with booting from usb (yes the usb is bootable in NTFS format). I got 2 usb's, one with windows 8.1 and one with windows 10. When i open up the BIOS and change the order to one of the usb sticks, the pc boots it and shows the windows logo again with the circling dots and then again goes to black screen. I'm sure it boots it because just before the windows logo pops out i see some text at the top left corner which says something like "NTFS.....booting image" or something like that. So I can't access my old windows, can't access cmd, can't install new windows. Now what?