Check AMDOvdctl
this? AMDOverdriveCtrl
Find a Windoze box, edit your video card with Radeon BIOS Editor, then pop it back in your miner.
i dont have any right now. im using linuxcoin on all my rigs. maybe after i get my HDD working ill put win7 on there but for now when i try to boot up it says no HDD connected.... even tho it has a HDD