In your device manager, go to "Display Adapter". Whatever is there, remove it and reboot. Install the correct driver when the machine restarts and says "Found New Hardware." You should have the driver disk. If not, go get the drivers off the web (not a bad idea anyway, even if you do have a driver disk).
If you don't know what kind of video card you have, call Compaq, look in your Compaq manuals, or open your machine and look.
I take it you have a 2D card and a 3Dfx Voodoo add-in card. <????>
Thanks Freon. It's a home-built PC, all of this was working fine under 95, but like I mentioned earlier, I had to format and start over (long story).
So, I really don't know what I've got; I've left a voice mail for the guy that built it; hopefully he'll be able to remember. Would that information be on the card/s, if I took off the cover and looked?
Display adapter = Standard PCI Graphics Adapter (VGA).
Ok. Sounds like you have a vanilla 2D card (probably a Trident, Tseng, or S3 of some sort) and an add-in Voodoo 1. You have a pass through cable in back, correct? One that goes from your video card to another card, then back out to your monitor.
All you should need to do is change that "Standard VGA" driver to the correct one. (there are other ways, but removing and rebooting is the simplest to explain)
No offense, but if you don't understand a lot about computers, you might want to consider a name brand PC with a 2 or 3 year tech support agreement. It's better than trying your luck in some forum and getting stuck in 640x480x4bit.