Systems Management BUS...
Assuming you're using Windows XP, I'll bet the Dell link below should get you the "ATI SMBus/Chipset" driver you need:
Chip Set: ATI SMBus / Chipset Driver
And here's more of their drivers for your computer model, just in case:
Hope this helps.
seen dem in my device manager, what r they n what driver do i download to get them to operate.....
amd sempron 3500+
1.8 ghz, 512MB RAM