I have a Sony Vaio PCG-7Y2L, VGN-N320E laptop. It came with Vista. I installed a new hard drive and loaded Win XP. I cannot find the driver for the sm bus controller on Sony's website. The motherboard is an Intel T2060 1.6 Ghz. I cannot find the driver for the sm bus controller that is undefined in the device manager.
Here is the link to the INF Chipset installation utility, infinst911autol.exe, which installs chipsets in several varieties of chipsets. It solved my missing "sm bus controller" driver.