Front USB ports don’t work. Uninstalled SM Bus Controller.

My USB ports were working. Suddenly a yellow question mark appeared under SM Bus Controller.
I couldn’t find an update and I accidentally uninstalled it. I have restored the computer to early stages but SM Bus controller still doesn’t appear where it should be.

I use Vista Premium and my chipset is Sis 648 (they don’t have the relevant update for the driver)

I tried my original drivers CD but no luck.

I would appreciate your help to resolve this problem because it’s driving me nuts.