I had the same problem with Realtek Controller. But after downloaded the new driver, and embeded into the Install.wim and fresh installed my pc the problem solved.
My IRDA remote control for Media Center also is not working, even the driver is properly installed & recognized.... That s*cks.................
The unknown driver is from the IRDA, not the Chipset as I have looked.... The problem is with the IRDA driver (incompatible with the Win8.1 even with the compatibility mode)... It was working on Windows 8 but has these issues with the 8.1, so not all things is working as well with this new build (including some of my apps)!!! I will have to wait for some update of the IRDA manufacter anyway, just like that.