Model: Viper V550
Operating System: Windows 98 (Note: might work with other versions of this os.)
Before downloading: Run Free Scan for Instant Driver Updates
Diamond Multimedia Viper V550 Driver. Hope this link helps. I used to run a Diamond V550 AGP (now its in a closet) before switching to an ATI card. I never "drove it hard" and I don't remember it giving me trouble. You might also try updating Direct X drivers from Microsoft too if you still have trouble.