Flash disk comes up as unknown devices

Connect your flash drive to your computer using an available USB port.

If your flash drive is not recognized, you'll usually receive an error that says "USB Device Not Recognized."

Click "Start" > "Control Panel" and open the system configuration by double clicking the "System" icon.

Navigate to the "Hardware" tab and click the "Device Manager" button to open the Device Manager.

Click the "+" next to "Disk Drives" and locate your USB flash drive.

A question mark icon should be shown to the left of the label.

Right-click the device name and select "Uninstall."

Open the "Action" menu at the top of the Device Manager and select "Scan for hardware changes."

This will scan your PC for any new devices.

Because you uninstalled the flash drive, it will be detected as a new device and the drivers will be reinstalled.

Click "Start" > "My Computer" and look for your flash drive.

If this process was successful, your flash drive should now show up under My Computer as a storage disk.

If its listed as an unknown device

Then right click on your flash drive select rename

Hope this helps

A USB hard drive is a portable external storage device that works just like a conventional hard drive.

The device is simply plugged into a USB port on your computer as you would connect a flash drive.

Unlike a flash drive, however, a USB hard drive can store a much larger amount of data.

If your computer will not recognize your USB hard drive, you can try troubleshooting steps to resolve the problem.

Plug one end of the USB cable into the port on your hard drive and plug the other end into the USB port of your computer. Ensure that both ends of the cable are connected securely.

Open "My Computer" (Windows XP) or "Computer" (Windows Vista/7).

The USB device should be listed as "removable disk" once it is plugged into the computer.

If it is not listed among the available drives on your computer, proceed to the next step.

Ensure that the data cable is working properly.

Try another USB cable if you have one available.

Disconnect all other USB devices from the computer as they may interfere with the operating system detecting the external hard drive.

Reboot the computer if the USB hard drive is still not recognized.

Plug the USB cable into another USB port and check to see if the device is detected.

If you are using a USB hub, remove the device and plug the external hard drive directly into a USB port.

If the computer still fails to recognize the device, the external hard drive itself may be experiencing a hardware problem.

Check the status of the hard drive in the "Device Manager" window. Under Windows XP, right click "My Computer" and select "Device Manager."

For Windows Vista and Windows 7, click the "Windows" button in the lower left corner of the screen, then type "Computer Management" in the search bar and press "Enter."

Select "Device Manager" in the "Computer Management" window. In the Device Manager window, click the "+" sign that appears beside "Disk Drives."

If the external drive is not listed, click "Other Devices" in the Device Manager window and see if an "Unknown Device" appears.

The external hard drive may have been detected but the device is not working properly.

If it is still under warranty, take the device to the computer store where it was purchased to have it repaired or replaced.

Hope this helps

hi.
the Driver of USB Controller is deleted (by a virus or something like that)
and you need to install some drivers.
so put the motherboard driver Disk in your drive and try to update the unknown device in your Device manager
or install complete drivers of the Disk.

try to open in another computer see if it opens there n get ur data first coming to the unknown device issue, firstly insert ur pendrive to usb slot firmly then refresh your comp for about 5 times wait till the drivers are installed open "my computer" n see if the pendrive icon is displayed if its displayed double click n start using . If the above procedure does not work first time do repeat it ur pendrive will work for sure

1st You download Webcam Driver.
A HI SPEED USB device plugged into a non HI SPEED
After this install the Webcam driver in the system.
Installation of Webcam Driver
Go to the control panel
Click on the System Icon
Click on the Hardware Tab
Click on the Device Manager s
Select the Unknown Device or printer device where yellow Question Marks sign on it.
Right click on it and uninstall it.
After this go to the top of the device manager and click on scan for hardware changes.
Driver installation Wizard start.
Brows Your Driver from the Hard Disk and click on next.
Driver will be install.

DOWNLOAD HP DISK FORMAT UTILITY THEN TRY THROUGH IT

have you tried putting it in a different usb port if you tried that try updating your computers usb drivers from the support site for the computer your trying to use the flash drives on

pen drives generally have 3 to 5 years warranty, if your pen drives are not detectng on other systems also, its better to replace it

unplug seagae usb external h/d
Device manager>Under usb= ,uninstall the device.
run: RESTORE, choose the last check point, reboot,then plug in the h/d in your usb.

u have to install drivers for usb connections.
i guess u have 98 version of windows. if u have windows 98 operating system u have to have install drivers for every USB devices.

feel free to ask me questions regarding this answer
chirag