USB connection for wireless mouse and keyboard not working

Hi, I have a relatively new Dell laptop (<1 year old) and I bought a wireless mouse and keyboard (also Dell) as a bundle with it. They have stopped working. The laptop doesn't recognize the dongle when I plug it in to any ports: it either doesn't see it at all, or says it's an unrecognizable device. They used to work fine! I've replaced the batteries and that's not it. I've restarted my computer, and no go. I've unplugged (and removed the battery) to see if that did anything: Nothing.

My cheap logitech optical mouse works just fine, so it's not that the USB doesn't work at all. I've seen other suggestions to delete the USB Root Hubs under Device Manager, but I'd like to hear from an actual Dell person that that's okay to do.