External HD and flash drives notrecognized?

The oddest thing happened – my computer suddenly decided, after three years, to no longer recognize my two external hard drives or my four flash drives. None of my six ports recognize them. They don’t load. Nothing. Just a little pop up saying something akin to “USB device not recognized by Windows.”

Hmmm. Non-storage devices like the printer, scanner, mouse and keyboard, all still work without a hitch on any of the ports. My HDDs and flash drives still work on my other home computer and my laptop so it’s not the devices themselves. This is really perplexing because I haven’t installed any new software in ages nor have I put in new hardware. This problem just seems so arbitrary! I was using these devices just yesterday, too!