Sm bus controller question?

I have the infamous yellow question mark. I've searched on here and googled it but can't seem to figure out what I need to download and install. I did a clean reinstall of xp pro and figured out everything else that was messed up with it. That's the last question mark and it has me stumped. The laptop seems to be working fine so is it even necessary? Any help would be greatly appreciated. Thanks. If you answer but need more info, please return to the question later/tomorrow and I will try to give it to you if I can. Not very computer literate right now.