i have been trying to fix this for almost 1 month now.... i had windows 8 upgraded to 8.1 and then i purchased ram upgrade so i could upgrade further with windows 10. i didnt like 10 tho so i tried to revert back to 8.1 primarily cuz windows 10 had a stuttering glitch problem and it was annoying. after the rollback process was finished i restarted pc only to have more issues than before. my pc wont boot into windows now i have made 2 usb drives trying to get it to boot into windows. one is of 8.1 and the other drive is windows 10 and neither one will boot all the way into windows either. it did however get me farther into the right direction because when i tried to just boot with my hdd without the usb bootable drives it would just say no bootable device detected. with the usb it allowed me to get past that part..... but now it always leads to black screen with one single line at top left of screen saying .....BI Initialize library failed 0xc00000bb.... please anyone help me solve this issue