I just bought a new video card: XFX 5750 1g gddr5 wich was a great improvement over my last Sapphire 4670 512m gddr3 and I'm having the weirdest problem: I uninstalled drivers, cleaned with driver sweeper, plugged in the new card, reinstalled drivers (11.1 for 64 bit W7) and everything seemed to work fine. I opened Metro 2033 to try out DX11 and y couldn't check above DX10... so I checked in AIDA64 and in catalyst menu and i noticed something weird: Catalyst reconized the 5750 with no problems but AIDA64 showed that i had two cards working, the IGP --> HD4200 from the mobo and the 5750 and in DXDIAG the primary graphics adapter was the HD4200 !!!!!!!!!!! so I was limited to dx10.1 of course... Now, games run as smooth as hell, so my my new 5750 is running fine, it also overclocked and stayed cool.. and for example mafia 2 is benchmarking lowest:29fps avg:40fps max:80fps with everything maxed out at 1920x1080 so i figured that the hd 4200 isn't interfering with the rendering... but i also know that these two cards are incompatible for Hybrid Crossfire and in the BIOS I have disabled the IGP and my primary graphics adapter is set to GFX0 (or PCIex). I have found that if i try to update drivers from the device manager and i choose the certified driver for the 5700 series, DX11 becomes availiable and DXDIAG checks the 5750 as my primary adapter and i can use dx11 in metro 2033.... buuuuuuuuut after I turned off the pc and restarted a few hours later, the same happened again... HD4200 was again in my way... now I have tried almost everything, resetting bios, reinstalling different driver versions after a full cleanup in safe mode with driver sweeper, updating bios to the latest version... etc. but this keeps happening. The weirdest thing is that with my HD4670 this didn't happen !!! Can ANYONE help me?? My mobo Asus M4A785T-M And the rest of my config is already in my profile. sorry for my english (I'm from argentina) And I'd appreciate ANY help or tip you could share ! Thanks !!!!