A few months ago I connected 4 (four) Dell 2009W monitors to a Dell OptiPlex 790 01. The OS was Windows 7 Enterprise (x64) Service Pack 1 (build 7601)
I used the original Dell proprietary connection type DMS059 to dual DVI to connect two of the monitors. I then installed a second graphics card mdoel Radeon HD 5450 and attached a DVI splitter to the other 2 monitors. This setup worked successfully.
Two weeks ago I dismantled the setup and moved it across the room and hooked them back up. Now, I can only connect to 2 of the monitors successfully. When I attempt to extend the desktop to the other 2 monitors they do not show up as a choice.
I have removed the display card and re-booted the computer with just one card installed. I still am able to view with 2 monitors.
When I re-install the display card and attempt to extend the desktop to these other 2 monitors i receive the same results.
Q: Why does it not work now?
It is the same setup as before when all 4 monitors worked successfully?