The best place to get up-to-date drivers for your machine is the manufacturers website. Check this is right, but for your machine I believe this is the correct link for your PC on the HP website.
Even though it doesn't specifically say anywhere, the SM Bus Controller driver is bundled with the Graphics Chipset Drivers. I only found this out after installing everything down the list after replacing my hard drive. Windows Update - Custom will often fill in a lot of blanks too.
Hope that helps