Disabling DEP in BIOS and Windows Bluescreen

Hi,

For some strange reason when disabling DEP on my Windows 7 32bit PC my computer will BSOD, I assume that the setting in the BIOS called "Execute Disable Bit" should fix this but it makes no difference.

I then re-installed Windows and when I disable the "Execute Disable Bit" option in the BIOS the computer crashes... I have to have it enabled or I can't load Windows...

Can someone please help me? My motherboard is a Gigabyte Z77-DS3H.