The problem is not with the monitor, it is with the graphics. From the sound of it you have VIA graphics and with Windows XP you can more than likely get the driver here:
http://www.via.com.tw/en/support/drivers.jspMake sure all connections are good, check in "device manager" and make sure your monitor is enabled and working prorperly and, check in "personaliztion" and make sure you have adjusted you resolution accoringly. If you provide me with the make and model of your system and, even better, the make and model of your motherboard, I can give you more accurate info. In VIA's link, you would want to'
Click on arrow next to system and scroll to "Microsoft windows"
In system, click on XP or XP64, depending on what you have
In driver, click on Integerated Grahics.
Then look for your S3 Graphics Pro but, knowing the chipset would be helpful.
Let me know if I can help you further.
Dave