What OS are you running, at this point I'm assuming XP or Vista, am i correct? What hardware is involved in this dual screen setup? If using a Dual DVI setup i'd do the following:
1) first uninstall your video card drivers, and reboot.
2) With your computer turned off, check the connections and see if they are in the following configuration ( assuming at this point you're using a dual DVI dongle, Y splitter)
2a) The screen on the left should be connected to "1" on the splitter
2b) The screen on the right should be connected to "2" on the splitter
3) Power on your computer, only the left one will turn on, don't worry.
4) If you have the disc for the video card that has the drivers, pop that in and when it auto executes, kill it from doing so.
5) Right click "My Computer">Properties>Hardware>Device Manager
5a) In the list, locate your "Display adaptor", right click on it and select "update driver"
6) In the following wizard you're going to make sure the second checkbox is selected and hit next, this will load the drivers directly from the disc bypassing the install shield provided by ATI
7)Reboot
8) Right click on desktop>properties>settings
8a) right click on #2 monitor and click "attached", also check the box that says "extend my desktop to this monitor"
9) set the resolution to both and reboot
10) Increasing the refresh rate from 60hz to 75 sometimes does the trick.
if you don't have the disc, go ahead by downloading and installing the drivers via the.exe file obtained.
Let me know if this helps.
