A couple of weeks ago I bought a 500 gig IDE Caviar and put it into an
external USB enclosure. It worked perfectly and I've taken a couple
of system backups to it. Trying last night to do a third backup I
found that the drive had vanished from My Computer and Disk
Management. Drive is seen in BIOS as a USB mass storage, and also in
Device manager, which shows it enabled and working properly. I have
uninstalled and reinstalled it, to no effect. The only program that
can "see" it is Belarc Advisor, which thinks it's a 2199.2 gig mass
storage. So part of Windows can detect it's there but it's not being
detected as a 500 gig HDD. Is this an enumeration problem? I might
add that no other hard or software has been changed.
--
Robin
(BrE)
Herts, England
(Robin goes on to say...)
Of course it is a USB enclosure with its own power -- an AKASA
Integral. I have two external USB devices with their own power: one
is 360 gig ASA, which I've put onto another computer as backup device,
and replaced it on my working machine with the 500 gig. I bought an
IDE enclosure / HDD (rather than SATA) because I have quite a few old
80 gig IDE HDDs which I wished to reformat before building them into a
third machine to give away. As I said, the AKASA / 500 IDE worked
perfectly through two backups as disk G. Now, out of the blue, it can
be seen by BIOS and Device Manager, but is invisible to My Computer
and Disk Management. Windows knows it's there but for some reason
cannot tell what it is.
This is an ASUS P3E5 deluxe board with 3x3 core2duo, 4 gig RAM, 1333,
3 SATA drives, XPPro SP3.
--
Robin
Robin:
These USB non-recognition problems (especially involving USB external HDDs &
flash drives) have been vexing all of us for some time now. Hardly a day
passes where queries similar to yours are not posted to this and other
newsgroups dealing with XP/Vista issues.
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...(I realize not all of the
following will have relevance to your specific situation, but they may be of
some value to others having a more-or-less similar problem as you're
experiencing).
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. Again, if the problem device is a USB external HDD that is not being
recognized by the system - access the BIOS and disable the "boot from USB
device" option should that setting be present in the BIOS. Ditto for "USB
legacy support" or similar setting if present.
8. Try alternate powering ON/OFF methods. If the USB device contains its own
power supply (as in the case of a USBEHD), try booting up with the device's
power on, and if the USBEHD is not detected, then try powering on the device
only *after* the system has booted to a Desktop.
9. Try a different USB cable.
10. In the USB controllers section of Device Manager, uninstall all the USB
controllers listed and reboot.
11. If the device in question is not a commercial USB external HDD but
rather one in which you installed a PATA 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 has never seemed to matter
how a USB external HDD (regardless of make/model) is jumpered when installed
as a USB device in an external enclosure. But I continue to see user reports
indicating a jumper change resolved their problem, so it may be worth a try.
12. 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 disk.
13. If the USB device is connected to a USB 2.0 PCI card, try changing the
card's PCI slot on the motherboard.
14. 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.
15. Determine from the manufacturer of your motherboard whether there's a
BIOS upgrade (or other software download) affecting USB device recognition.
(We have encountered a few - very few - older motherboards (about five or so
years old) that exhibit USB 2.0 connectivity problems, even though they're
presumably designed for USB 2.0 capability and the installed XP OS includes
SP1 or SP2. (I'm assuming your PC contains a SP since there were definite XP
OS-related USB-connectivity problems prior to the SP1 update). In a number
of those cases involving a motherboard problem an additional USB 2.0 driver
was included with the MB or available from the motherboard's manufacturer.
Theoretically there should not have been any need to install an auxiliary
USB 2.0 driver, but we found this was the only way to ensure reliable USB
2.0 connectivity. Admittedly this was a rare situation with only a very few
motherboards and we haven't encountered this identical problem with
motherboards manufactured over the past five years or so.)
Anna
P.S.
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