Windows 8 and 7 install help

Hi I got windows 8 64 pro installed but I am having problems with memory which is causing black lines on desktop and even in bios. I wanted to install windows 7 on another partition but windOWS disk tells me I can't because of gpt boot. How can I fix this ,sould I do a clean install and start over to use Mbr?Thks
What do I need to enable or disable in bios for mbr? Thks

As the your MOBO's has a uEFI BIOS.
Both Windows 8 x64 & Windows 7 x64 support uEFI BIOS.

How to install Windows 64 bit on a uEFI BIOS:

UEFI (Unified Extensible Firmware Interface) - Install Windows 7 with - Windows 7 Forums

http://www.eightforums.com/tutorial...e-firmware-interface-install-windows-8-a.html



For more info on uEFI:
Windows and GPT FAQ
Unified Extensible Firmware Interface - Wikipedia, the free encyclopedia
UEFI and Windows

You could try installing Windows 7 first.

Many thks i'll read up on this

You are welcome, I hope all goes well.