I'm unsure what triggered this change, but all of a sudden neither my keyboard nor my mouse work in Windows 8.1. I've tried an alternate keyboard as well as an alternate mouse and no luck. I've changed my mobo recently, but it was working for a week before this happened. Messing with legacy USB options and keyboard and mouse support in the bios did nothing. No matter what USB port I use, they all work in the bios, and none of them work in W8. I also cannot get to the advanced boot options via USB. Can anyone help?