Open GL problem

I am working on an AMD Duron 800Mhz running Win98se. I have reformatted and loaded and get a fatal page error every time I run the Open GL query. I get the same error if I select any of the 3D Windows screensavers (any others are OK). The machine runs onboard graphics (SIS) and I have tried default bios settings. If its any clue, when I run msconfig, nothing appears in the Config.sys ? ? I have also tried reformatting and reloading again. Any ideas???