Had a frustrating afternoon trying to get my triple-monitor setup going again; I had WinXP for years with two video cards: a single, simple VGA / PCI card, and a recent Radeon HD 4670 card with two outputs. Under XP everything was recognized without incident, first repeating all three monitors and then able to extend windows to this monitor under Display Preferences.
Now under Windows 7 RC, I did a fresh install with both cards inserted, and only the single VGA card would drive its monitor. The HD 4670 drivers are listed in the Device Manager, I removed and installed the ATI 9.9 version software several times, and the single VGA output is the only thing I get. I even tried the 'F8', selected the unsigned drivers, and still it didn't bring the Radeon to life.
I pulled the single VGA card out, and bam the two monitors off the Radeon come alive. I install the CCC and it works just fine. And then I shutdown, add the VGA card back, and get the single VGA output again.
Other than getting a newer video card (hey, I could go for a fourth monitor), any other ideas or suggestions? I've learned a lot this afternoon reading up on all the interesting Win7 stuff here - thanks for any help.