Method 1: Use Device Manager to scan for hardware changes
loadTOCNode(2, 'resolution');
Use
Device Manager to scan for hardware changes. After your computer scans
for hardware changes, it might recognize the USB device that is
connected to the USB port so that you can use the device.
To scan for hardware changes, follow these steps:
- Click Start, and then click Run.
Note If you are running Windows Vista, click Start, and then use the Start Search box.
- Type devmgmt.msc, and then click OK. Device Manager opens.
- In Device Manager, click your computer so that it is highlighted.
- Click Action, and then click Scan for hardware changes.
- Check the USB device to see whether it is working.
If scanning for hardware changes fixed the problem, you are finished. If this method did not fix the problem, go to Method 2.
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Method 2: Restart the computer
loadTOCNode(2, 'resolution');
If
scanning for new hardware did not fix the problem, try restarting the
computer. After the computer has restarted, check the USB device to see
whether it is working.
If restarting the computer fixed the problem, you are finished. If this method did not fix the problem, go to Method 3.
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Method 3: Disable and re-enable the USB controller
loadTOCNode(2, 'resolution');
Use
Device Manager to disable and re-enable all the USB controllers. This
lets the controllers recover the USB port from its unresponsive
condition. The USB controllers represent the USB ports in Device
Manager. If you are not comfortable with advanced troubleshooting, try
the steps in the "
Workaround" section.
To disable and re-enable the USB controllers, follow these steps:
- Click Start, and then click Run.
Note If you are running Windows Vista, click Start, and then use the Start Search box.
- Type devmgmt.msc, and then click OK. Device Manager opens.
- Expand Universal Serial Bus controllers.
Note You might have to scroll down the list to find this item.
- Right-click the first USB controller under Universal Serial Bus controllers, and then click Uninstall to remove it.
- Repeat step 4 for each USB controller that is listed under Universal Serial Bus controllers.
-
Restart the computer. After the computer starts, Windows will
automatically scan for hardware changes and reinstall all the USB
controllers that you uninstalled.
- Check the USB device to see whether it is working.
If the USB port recognizes the device and if you can use the device, you are finished.
If this method fixed the problem, you are finished. If this method did not fix the problem, go
to the "Workaround" section.
what's the next step
Can you please share the solution? I have the same problem. Did it have to do with the registry? Many thanks, Joe
usb stopped working. system restore doesn't fix it. updated drivers don't fix. uninstalling and re-scanning for new hardware doesn't fix.
there is a constant Unknown usb device in the device manager, even though nothing is plugged in.
usb stopped working
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