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Wed 31 Dec, 2008 01:29 am
Windows XP service pack 3
I recieve a message balloon giving the following information:
"One of the USB Devices attached to this computer has malfunctioned and windows doe not recognise it. For assistance on solving this problem click this message."
When i click the message I get a pop up screen that shows;
Root hub [2 ports]
|_unknown device
|_unused port
I have systematically disconnected all the usb devices, camera, printer, external hard drive, including keyboard and mouse.
The message continues to appear.
I have systematically reconnected and tested each device. Keyboard mouse and printer all work fine. Camera and external hard drive are not recognised however they both operate sucessfully on other computers.
I have recycled the computer:
Shutdown was not affected in the normal manner. A black screen appeared however the computers green active light remained on. It was necessary to hold the power button down for 10 seconds to effect shutdown.
Start up was ............difficult. I was able to start in safe mode and using "last known good configuration"
Virus scans and checkdisk showed nothing.
any advice on this would be appreciated
Have you checked Windows Update to see if there are any new drivers for your peripheral devices?
Also, if you have narrowed down possible malfunctions to certain devices and there are no driver updates, you might have corrupt driver files. Removing and reinstalling them via Device Manager may fix it, especially if they work on one computer but not the other. That points to it being a local problem on the PC and not any of the devices themselves.
Was just reading through the Windows tech forums and noticed that another frequent cause/solution is the USB cord for the device.
Thank you butrfly for your input. Those are all reasonable suggestions. I have auto update for windows so I know I am up to date and ran several virus scans and clean up programs.
I have now solved this problem.
There appears to be a problem with the power management system of the Universal serial bus controllers. The USB root hub(s) have an option to "allow windows to turn off this device to save power"
After a lengthy period of inactivity (in my case 3 days) the computer does not does not return the USB root hub to activity.
The solution Is very easy.
Turn off the power at the wall socket, remove the plug from the wall socket, wait 1 or 2 hours. Plug in to the wall and restart the computer. This appears to drain power from the motherboard and reset the power management system.
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