I downgraded from Windows 7 to Wxp and everything worked except for the yellow exclamation mark on "audio device on high definition audio bus". Six hours of reading every thread posted and I eventually found the solution. This seems to be a multimedia device, not just for sound. One post directed me to the Intel website to download Intel's driver updating tool. I ran this on my computer and it showed all drivers valid except for my video device. It offered an updated video driver for the Intel (R) HD Graphics Family, which I took and immediately solved the problem. No more exclamation marks!