It's always possible that something went bad with the generic windows usb driver or that for some reason one device didn't disconnect properly. Have you tried rebooting without the keyboard and ...

Why does my computer say USB device not recognized? When you connect your USB device to a Windows computer, it will be displayed in the Windows Explorer or File Manager only if your computer ...

USB port not recognizing your device? Learn the common causes and step-by-step fixes to get your connection working again quickly.

If your Android Device is not recognized by your Windows PC while trying to connect them via a USB cable, use these fixes to resolve the issue.

Problems with USB devices For some users, USB devices become inoperable -- either not recognized or not functioning properly -- after the Mac OS X 10.3.6 upgrade.

Solution 3: Disable USB selective Suspend Setting There are times when USB devices are not being recognized because of the USB selective settings.

If you're having problems with FireWire or USB devices not being recognized or interacting properly with the system, you may want to try cleaning caches with a utility like Cocktail, Mac Pilot or ...

Sometimes though, it'll give me the "usb device not recognized" error, and I have to turn the printer back on and off again, then reboot the monitor again. PITA.

USB port not recognizing your device? Learn the common causes and step-by-step fixes to get your connection working again quickly.