I have the same exact problem. I also happen to have a second hard drive with Windows on it and when I boot to that drive my keyboard and mouse worked just fine it's not a USB port issue at least any physical failing. This is some sort of corruption due to either an update or random corruption of the drivers though seeing how this is a fairly common issue common enough that there are plenty of posts about it I doubt that it is random corruption to the keyboard and mouse drivers. It also happens to cross many different models brands of keyboards motherboards etc the only consistent thing is Windows and the failing of the keyboard and mouse during boot up after bios prior to login screen. what gives?
I would prefer not to use such a heavy-handed solution as resetting windows. I mean that doesn't really fix anything you just start over. It's kind of like saying you fixed your car by buying a new one.