Rig won't get past windows loading screen with graphics card power plugs in

[RoRHemi]

Ok, so I recently made the stupid mistake of flashing my 5850 with the wrong bios, and I've bricked it. Well, I have an old 5450 lying around that I figured I would run off of to get into windows and re-flash the old card. With just the 5450 installed, it all booted fine and dandy. Now, upon installing the 5850 in the second slot and plugging in the power cables, it gets stuck at the Windows 7 loading screen. (After the logo has pulsed for maybe 6-7 seconds) If I unplug the power from the 5850 it'll boot up no problem, but with it in it cycles through the repair mode and gets stuck at the windows loading screen each time. I assume the 5850 won't be detected by windows unless it has power either, so I am stuck here. Is there a way for me to get windows to find the card without the power in? System wouldn't boot at all with 5850 in the top slot either.

 

[plasmastorm]

try booting in safe mode to see if it's just a driver issue. other than that put the bios file on a bootable usb stuck and boot from that to reflash it in dos without worrying about windows