On Fri, 15 Dec 2006 14:12:32 -0500, "Anna" <myname@myisp.net> wrote:
>
>"Ron Carr" <RonCarr@discussions.microsoft.com> wrote in message
>news:17DD5C7B-A43D-41F3-97A3-5B4415E4B369@microsoft.com...
>> When I plug in a USB external disk drive, or a flash memory card, the
>> device
>> does not show in Windows Explorer. Disk management shows the disk drive
>> (not
>> the flash memory) but it has no drive letter and I cannot assign one
>> (Change
>> drive or path grayed out). I do have an E: drive which is evidently the
>> memory card port on my photo printer - never used. (I have 2 hard disks C
>> and
>> D, my CD and DVD are assigned P and Q).
>> Thanks for any help.....I threw away a flash memory card figuring it was
>> no
>> good!
>> Ron
>
>
>Ron:
>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.
>
>Be that as it may, we've put together a more-or-less checklist for
>troubleshooting these USB non-recognition problems that (hopefully) may be
>of some value to you and other 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.
>
>A number of posters have reported they've found useful information re
>troubleshooting USB devices on this site -
>http://www.uwe-sieber.de/usbtrouble_e.html
>Anna
>
>
Another problem I have found is that the HDD can be corruptly
formatted, which isn't so easy to detect actually.
Reformatting the drive non-corruptly corrects the non-drive letter
situation.
I've found the Acronis True Image disk utilities seem to accurately
diagnose corrupt disk formatting and then correctly format badly
formatted HDDs.
I've been caught out with a USB2.0 hard drive being set to slave when
it ought be set to master too. Some USB2.0 HDD enclosure instructions
specifically state the drive _must_ be set to master.
Ross
(To get email address ROT 13)
ebff_qnyl@lnubb.pbz