Rick is right. I have an older Microstar 6330. It supports only up to an Athlon 1.4ghz. I tried putting a faster chip in it but it wouldn't boot. So I had to put the old one back in. It was manufactured by gateway. The funny thing is the older chip was really solid, heavier, and thicker than the new one. Feels like a fishing weight! You might want to get on Compaq's website, maybe if you input the serial # of the system where you pulled the board, it could tell you if the CPU is upgradable. My 6330 doesn't have an HD light. Only a power on light. And it only supports USB 1.0 BTW- check this link: http://forums.amd.com/index.php?showtopic=2971 They're talking about the same issue. They say this: "For sure, you should be able to upgrade to a Palomino XP2100" you might require a BIOS update.