YesAre they USB 2 or 3 - Is that your problem?
Done that..Remove all USBs from the ports and try rebooting, sometimes it 'wakes' them up ...
Tried and failed...+1. Use Device Manager to 'uninstall' them. Reboot, and it'll re scan for them and reload the drivers.
Right Click Start (bottom left corner)Tried and failed...
Found a number of these...Right Click Start (bottom left corner)
Left click "Device Manager"
Does anything there have a red cross or yellow triangle showing on it?
Scroll down to "Universal Serial Bus Controllers"
Do any have a red cross or yellow triangle?
If yes - Right click and "Uninstall device"
Confirm you want to uninstall it (Its just the drivers that will uninstall. When you reboot the system will detect it as a "new" piece of hardware, then look for an load the latest driver, and re-install it).
Close everything and Re-Boot.
If not - Right click each one in turn and
Select "Update driver". Select "Search Automatically..."
Do that for each one.
If any of them update, reboot.
If they still dont work, Right click start,
Left click "Event Viewer"
Select "Windows Logs"
Scroll through the "Errors" for the date and time you had the problem, double click the entry to read it and if it seems USB related then either cop and paste the text into Google and search for an answer (or paste here).
NB There will be zillions of entries in the log and despite the best efforts of various foreigners of the Indian persuasion to tell you otherwise they are, mostly, just messages for techies to fault find and not the end of the world and do not need you to do anything / download anything at all.