I have recently had to reinstall the software that came with my pc (e machine E4040 desktop pc windows XP pentium 4 processor 517) it all seems to be working fine apart from when you look in the device manager the SM Bus controller has an exclamation mark next to it and when you click on it it says device not working correctly. Have sent e machines several emails but not got any reply and e machines in the US wont help because its a UK machine. Looking on the web there are loads of sites offering info/ downloads but non specific for this machine.
All I need to know is
What is it
What does it do
Do I need it
And where can I get it
Steve 
It is a driver that is not included on an e machines (Gateway) recovery disc, but an internet search finds this.
intel.com/support/chipsets/sb/cs-013541.htm
To be honest if everything else is working. I wouldn’t worry. Try a PM to Lonewolf, he has passed his exams 
If you do this, set a system restore point first, then if it all goes ■■■■ up, the pc will still work… 
Here’s a forum post that may help Clicky
Though as WN says it’s not vital. If sound, vision and USB are all working Ok, you can ignore it.
I had the same problem with a Dell Optiplex that I rebuilt While I did find the driver, everything else was
working OK before I installed it…oh and after.
Many thanks will look at them at the weekend when I have more time
Steve