I am trying to downgrade a friends Asus X551MA from windows 8.1 to Windows 7. After much messing about i finally figured out how to get the bios to boot from cd/usb. During installation it crashes BSOD. Error message refers to the BIOS. I looked online and reference to using Rufus to create a UEFI bootable windows 7 image on a USB but this also crashes with exactly the same error message. I have run Memtest86 and results were good. I also tried installing NT which starts to install and then the screen goes weird like your loading a spectrum game. I also tried xp,xpsp2 and xpsp3 they all get the same error message as windows 7 except with an extra paragraph about pressing f7 to turn something off. Ill post the images of the error message asap im just looking for the charger! Any ideas guys??? Any advice is greatly appreciated. Ive downgraded so many times before and on many different brands of laptop/desktop and never before encountered this issue.