ATI Radeon HD 3800 Series cannot detect all monitors

Need to know what operating system you are using?

we are using windows 7 64 bit

The 3800 has a dual ramdac so even if it has 3 or 4 outputs you can only use 2 monitors at 1 time.

prior to updating drivers this morning the system was working fine with all four monitors

4 monitors? Do you have two cards with two monitors a card? What exactly is your setup?

There are two ATI Radeon 3800 series cards with two monitors attached to each when working. In device manager the two ATI cards are showing up but only two of the four monitors are showing up under monitors since updating ATI drivers

Check to see if crossfire is enabled. If it is, disable it. You may also want to consider downgrading the display drivers to the last version you were using. You would have to uninstall the drivers first and use driver sweeper to remove any traces of it before installing the old drivers.

How do I disable crossfire? Need latest drivers to run the 3D graphics of a reservoir simulator.

Just go into Catalyst Control Center, click on the top left area to bring down the main drop down box, and select "CrossfireX". If it's enabled just disable it and you should be good to go.

There is no Catalyst Control Center on machine? Is there another way to access"CrossfireX"

Thanks megamanx00 - all up and running now

Best answer selected by atech101.