no sound all of a sudden vista x64

I installed vista x64 a few weeks back w/o a hitch and have been running smoothly since last night when I boot in and it says I have no sound device installed. I went to realtek.com to get the latest driver (ver. 1.89) and installed it; however, when I rebooted and came back on...it still says no sound device is installed. I check my bios to make sure onboard sound is still enabled and it is.

I went into device manager and noticed that "PCI simple communications controller" had a question mark beside it...could this be the culprit? Where could I get the driver for this? My computer is a Gateway GM5638E and Gateway's site is not very helpful...I may give them a call later but thought I should see if I could get some help here first.