First post and my first build

i5-3450

2-Radeon HD 7850 2gb crossfire with the new Beta drivers.

asrock z77 extremem4 mobo

win7 x64

I was able to make crossfire turn on when I turned  the qpu buffer on.  I had the settings set at Ultra.  It was running fine but I had a little bit of a sound issue, nothing major, so I turned the graphics down to "very high" and I think that's when it turned off, I think anyway, I wasn't paying that close of attention.  Now it won't turn no matter what settings I have.  It does run good with one card but just curious why.

Open CCC and go to this page. Make sure crossfire is enabled.

Gaming Rig
Gigabyte GA-P67A-UD7-B3 F7 bios
i7- 2600k ,Cooler Master V6GT
2x4 gig G-Skill Ripjaws X DDR3 1333
Asus GTX 680
Corsair TX 850W PSU
Creative X-FI Titanium Champion, Logitech Z-5500
Win 7 x64 Ultimate(SP1), Antec DF-85 case.

Thanks for the reply.  Yes I have it enabled.  It works with my other games just not with Farcry3.

Intel I7 960 @ 3.87ghz *Intel DX58SO *HIS HD6970 2gb *Corsair TX650M *2x4gb Corsair XMS3 *WD Black 1TB *Windows 7 Home Premium 64bit *Gateway HD2401 24" 2ms 1920x1200  ***Asus N71Jq laptop *Intel I7 720QM Processor *Mobility Radeon HD5730 1gb *8gb Ram *Windows 7 64bit  ***Acer 5750 laptop

* A clear conscience is usually a sign of bad memory *

after you said to uninstall I did, and still not working.

Disable ULPS. Google it.

Go to registry and disable Ulps:

[HKEY_LOCAL_MACHINE\\SYSTEM\\ControlSet001\\Control \\Class\\{4D36E968-E325-11CE-BFC1-08002BE10318}]

and change "EnableUlps" to 0 under the 0000 and 0001 and 0003 keys.

Intel I7 960 @ 3.87ghz *Intel DX58SO *HIS HD6970 2gb *Corsair TX650M *2x4gb Corsair XMS3 *WD Black 1TB *Windows 7 Home Premium 64bit *Gateway HD2401 24" 2ms 1920x1200  ***Asus N71Jq laptop *Intel I7 720QM Processor *Mobility Radeon HD5730 1gb *8gb Ram *Windows 7 64bit  ***Acer 5750 laptop

* A clear conscience is usually a sign of bad memory *