I’m not sure what happened here, but I thought I’d post it and see if anyone else has had the same problem.
Yesterday, I moved my HP Windows 7 machine from one room in my house to the other. When I reattached everything and turned it on, the keyboard and mouse wouldn’t work. I mean, it’s as if they weren’t connected. I tried the troubleshooting on the HP website, but didn’t come up with anything more promising than “replace your computer”. Yet the computer worked fine; it booted up okay, I just couldn’t interact with it.
Eventually, I fished out an extra keyboard and it worked. An extra mouse, however, didn’t. I bought another mouse today, and it worked.
So what happened? Well, I noticed at one point that I had the wrong power supply connected to my USB hub. My theory is that anything connected to the hub while it had the wrong power supply got fried. After I corrected the power supply problem, any new equipment worked fine.
I would never have thought that an incorrect power supply on a USB hub could wreck peripherals like keyboards and mice, and I still don’t know if that was the cause or if it was just a run of bad luck, but I know I’ll check that power supply the next time I move the computer.