If you use 2 or more cards, only one will be AGP... the other(s) will be PCI. (You can use 2 PCI and bypass AGP, too). It is VERY important that you know your video drivers are compatible with your system and each other before you install them. At the least, you just won't get the desired result. The worst?...You may just enter "Video Driver Hell", which could possibly require you reinstall your entire system from scratch. Conflicting video drivers is an experience you're not likely to soon forget. (If possible, you should "image" your HD somehow before trying to install 2nd video driver... Roxio Go Back, or Norton Ghost)
My system started acting weird, hanging a lot. So following your advice, here's what I did: 1-Used XP's System Restore and restored my computer to the time just before installation of the new video card. This wiped out all the MSI/nVIDIA files. 2-Powered down and installed the old video card. 3-Booted up and unistalled the old Diamond Fire GL video drivers using XP's Device Manager. 4-Powered up to be sure any changes to settings at reboot take effect and powered down before XP's auto detect tries to install drivers. 5-Installed the new MSI/nVIDIA card & attached just the monitor I want to use as primary. 6-Booted up in Safe Mode by pressing F8 to prevent all but the most minimal drivers to be loaded. 7-Chose Cancel when asked to install drivers for newly detected hardward. 8-Ran nVIDIA's (NOT MSI's) driver install prog. 9-Configured the monitor as I like it. 10-Powered down. 11-Connected 2nd monitor. 12-Booted up and configured second monitor. Sounds like I went through hell, but it was actually more like purgatory. When my system starts acting weird, I find it's best to try to nip any probable causes in the bud. So I took your advice and got rid of all the drivers as best I could. It seems to be working okay right now *fingers crossed*. Thanks again.