How to "restart/repair" an USB port?

"None of the answers quite answer the title question.

How to “restart/repair” a USB port?

There are three ways to ""restart"" a particular USB port:

Reboot the computer. Or ...
Unplug, then re-plug, the physical device connected to the port. Or ...
Disable, then re-enable, the USB Root Hub device that the port is attached to.

In Windows you'd do (3) through the Device Manager or via the devcon.exe utility.

The reason these are the only methods is due to the USB handshaking protocol, which is initiated by the USB device when it's plugged in, not by the controller. This causes problems like being unable to remount a USB flash drive after you've Safely Removed it. But cycling the USB Root Hub device causes all the devices attached to that hub to reinitialize themselves. (The unfortunate side effect is that it causes all devices attached to that hub to reinitialize themselves, which could be problematic if you have other devices on that hub which are in use.)"

"I had issues with Windows 7 dropping the USB mouse driver and reinstalling the mouse driver (most of the time) which was annoying as hell.

I tried all kinds of things to fix the problem, driver updates, clean boots, tech support phone calls, Internet software voodoo, but in the end I only had to reset my USB ports.

I did this by turning the computer off, unplugging all USB devices, removing the laptop battery and AC power supply, and finally holding down the power button for 30 seconds.

This fixed a problem that I must have spent at least 20 hours trying to fix; give it a try."

"Go to Task Manager, and you will find a warning label on the device you are having problems with. Just unplug your device, and put it into another computer or laptop. If it works on other computers it's definitely a problem with your USB port. Try replacing it, contact experts, and change it. Try it, and it will work definitely. If you find problems please change your motherboard. Please don't buy a new one because the device has no problem.

And if any of that didn't work, try USBDeview. It lets you view all installed/connected USB devices on your system. You can read more about it on its download page."
"Go to Task Manager, and you will find a warning label on the device you are having problems with. Just unplug your device, and put it into another computer or laptop. If it works on other computers it's definitely a problem with your USB port. Try replacing it, contact experts, and change it. Try it, and it will work definitely. If you find problems please change your motherboard. Please don't buy a new one because the device has no problem.

And if any of that didn't work, try USBDeview. It lets you view all installed/connected USB devices on your system. You can read more about it on its download page."

"Here's how to reset your USB after a power surge or other anomaly that causes devices to not register with the system:

Start
Control Panel
Device Manager
Right Click on Universal Serial Bus Controllers
Click Scan For Hardware Changes."

"Go to ""Device Manager"" (open Control Panel in ""Start Window"")
Go To ""Universal Serial Port controllers""
Look for ""Exclamation Point"" on one or more of the controllers
(Right click mouse) Disable, then (right click mouse) Enable
Done!!"