Super User is a question and answer site for computer enthusiasts and power users. It only takes a minute to sign up.
Sign up to join this community
My laptop has two USB ports, but one is broken, so I use a USB hub in the other good USB port. In that USB hub, I use a mouse and keyboard. Suddenly, that USB port doesn't detect the mouse and the keyboard (even with the light of the hub is on), and the only solution that I found is restarting the laptop. But just some minutes and the keyboard and mouse goes undetected again...
Is there some method, software, etc. to "restart/repair" the USB port without restarting the PC?
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:
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.)
You should look at NIRSOFT's USB Device view (http://www.nirsoft.net/utils/usb_devices_view.html). I have used this to fix a system that had a disconnected U3 USB drive still mounted preventing anything else in the port being recognized.
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.
If you have no power supply added to the USB hub, check if that helps. Maybe the laptop doesn't have not enough power on the USB; some older laptops didn't have not the full 500 mA.
Can you check your event viewer for any obvious errors in the application or system logs?
I don't know what the problem is at this point, but you should inspect the drivers installed. Are they Microsoft default input drivers or custom drivers? You might need to reinstall the drivers. It could be possible that the instance of the drivers is failing.
Also try inspecting the drivers after plugging in the device. You might see a resource conflict or some other warning in Device Manager.
Since the problem is occurring for two different devices, I think it's less likely a hardware failure on the mouse or keyboard.
The failure is definitely on your laptop.
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.
I'm not very computer knowledgeable, but I was having a similar problem with USB devices occasionally malfunctioning by receiving power but not working: e.g. mouse and/or keyboard lighting up but suddenly not functioning, when plugged into a particular USB port. The only workaround solution I found that worked, other than turning the computer off and on again, was to change my laptop's power setting to "hibernate" rather than "sleep" when I pressed the laptop's power button, and then going into and back out of Hibernation mode.
To change the setting in Windows 7:
Click on the "Windows" button [bottom left of screen] >
"Control Panel" [right-side panel] >
Hardware and Sound >
"System and Security" [left-side panel] >
"Power Options" >
"Choose what the power buttons do" [left-side panel] >
"When I press the power button:" [change to "Hibernate" - either "On battery", "Plugged in", or both, depending on preferences - my personal setting is "Sleep" on battery and "Hibernate" when plugged in]
Click the "Save changes" button
Next time you have the problem you can then press the power button on your laptop (if plugged in or on battery, depending on settings) and enter Hybernation mode. Be sure to stay in hibernation mode for long enough that the devices power off (lights on keyboard/mouse turn off, etc.) When you wake up the laptop again the USB ports may be functioning properly again.
I have not tried this method by choosing to simply enter "Sleep" mode rather than "Hibernate" mode when pressing the power button, but when I've left the laptop inactive for many hours it makes no difference to the problem.
Obviously, this method might only work for a laptop rather than a desktop PC, and if you're having the same problem re-occur every few minutes then it would not be very practical, but for anyone having this happen only occasionally then this might be a viable workaround. I think that it's a good idea to save your work if possible before hibernating the computer.
Here's how to reset your USB after a power surge or other anomaly that causes devices to not register with the system:
*Note I take no responsibility for ANY damage this causes to you or your computer following these directions. The responsibility and usage of these methods is solely on you.
Method I:
Open System Control Panel. (windows key + pause break)
Click Device Manager.
Expand Universal Serial Bus Controllers.
On Every Device Starting From The Top Called "USB Root Hub"
A. Right-Click
B. Select Properties
C. Click Advanced Tab
D. Click Reset Hub
Method II:
-Remove parenthesis and use actual symbol for Asterisk. Sorry Forum removes them in the post so I can't type them literally.
Some USB ports may report restart required. These hubs may unfortunately not be restarted without a reboot.
Up-vote if it helps so more will see. Came here myself via google search and was able to accomplish what I needed in both methods I listed above.
Enjoy.
this worked better for me 1] Enable, Disable USB Drives & Mass Storage Devices using Registry
Go to Start > Run, type “regedit” and press enter to open the registry editor Navigate to the following key
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\USBSTOR
In the right pane, select Start and change the value to 3. (The value 4 will disable USB Storage). Click OK. This will re-enable USB Ports and allow you to use USB or Pen drives.
