Uwe Sieber said:
Michael:
In addition to perusing the information on Uwe's site re this USB
non-recognition problem...
These USB non-recognition problems have been vexing all of us for some time
now. We've become increasingly convinced that the relatively large number of
problems in this area involving the non-recognition of USB devices that
we've all been experiencing is an indication that there is something
seriously flawed with respect to either the USB 2.0 specifications, possibly
involving quality control issues affecting the manufacturer of these USB
devices as well as supporting components such as motherboards and other
USB-related components. Then too, we've become increasingly suspicious of
the XP OS as it relates to its recognition of and interaction with these USB
2.0 devices.
We have encountered far too many unexplained problems affecting
detection/recognition of these devices and their erratic functioning not to
believe that something is seriously amiss in this area.
We continually encounter situations where a USB 2.0 device - generally
involving a flash drive or USB external hard drive, will work perfectly fine
in one machine and not in another. And, in far too many cases, we're unable
to determine why this is so since we're unable to detect any
hardware/software problem in the balking machine that would cause this
non-recognition effect.
We've put together a more-or-less checklist for troubleshooting these rather
common USB non-recognition problems that (hopefully) may be of some value to
users encountering this type of problem...
1. Access Disk Management and see if the USB device is listed. If so, and
there's no drive letter assigned, see if you can assign a drive letter to
the device.
2. If the USB device is listed in Disk Management with an assigned drive
letter, right-click on its listing and select Explore from the submenu.
Hopefully, Windows Explorer will open and the device will be listed.
3. Connect the USB device *directly* to a USB port on the computer, not via
a USB hub. Try different USB ports should your computer have multiple ports.
4. Avoid using a USB extension cable.
5. Try connecting a USB device (that does not contain an auxiliary power
supply) to a USB port both before and after the boot operation.
6. Where a USB (or Firewire) external HDD is involved, access Device
Manager, highlight the Disk drives listing and click on the Action menu item
and then the "Scan for hardware changes" sub-menu item. Do the same in Disk
Management > Action > Rescan disks.
7. Try alternate powering on/off methods. If the USB device contains its own
power supply, try booting up with its power on, then try powering on only
*after* the system has booted to a Desktop.
8. Try a different USB cable.
9. In the USB controllers section of Device Manager, uninstall all the USB
controllers listed and reboot.
10. If the device in question is not a commercial USB external HDD but
rather one in which you installed a HDD in a USB enclosure, jumper the HDD
as Master (or Single if the HDD is a Western Digital disk). A number of
users have reported that jumper configuration corrected their
non-recognition problem. In my own experience it didn't seem to matter how a
USB external HDD was jumpered. But it may be worth a try.
11. If the device in question is a USB external HDD, first check out the HDD
with the hard drive manufacturer's diagnostic utility. If it checks out OK,
and you can remove the HDD from its enclosure (without voiding any
applicable warranty), do so and install the HDD as an internal HDD to
determine if there are problems with the drive.
12. If the USB device is connected to a USB 2.0 PCI card, try changing the
PCI slot to which it's currently connected to another one.
13. Access the website of the manufacturer of the USB device to determine if
there's any firmware update or info re the problem you're experiencing or
there's any possibility that the USB enclosure itself might be defective.
14. Determine from the manufacturer of your motherboard whether there's a
BIOS upgrade affecting USB device recognition.
Anna
