Just an Update: I hooked up our old Dell Monitor to the Gateway and it's the same problem. Low resolution and it won't let me adjust it so the problem is in the computer. Lucky me!
We booted up our Gateway Desktop 500XL Desktop today and the screen on the FPD1530 Color Monitor was at its lowest resolution. I checked it in Properties and it is set at Lowest Screen Resolution and lowest color (4 bit). The arrow for the resolution will not move and the dropdown for the bit will not respond. I checked all the connections, tried the Troubleshoot and pressed the 'Autoset' on the screen but still nothing has fixed the problem. This may or may not be related, but when we are online we keep getting the prompt to install 'Active X' so we did but now MSN kicks us off the Internet every minute or so because of a problem. Once the Active X was uninstalled we had no interruption on the Internet.