Intel’s official site or your motherboard manufacturer’s support page.
Some users have success forcing the Chipset SMBus driver from the Intel Chipset Installation Utility. pci simple communications controller driver windows 7 64 bit
Does anyone have a reliable download link or know which Intel driver package includes this? pci simple communications controller driver windows 7 64 bit
(from Device Manager → Properties → Details → Hardware Ids): pci simple communications controller driver windows 7 64 bit