Vista is not assigning driver letters to external drives, claiming "Unknown Device"

My Vista Ultimate laptop stopped assigning driver letters to new external
drives, whether external hard drives or thumb drives. Old thumb drives I
used in the past are still recognized. This problem is happening on my new
Western Digital 1 tb external drive, whether using USB 2 or Firewire 400.
It is also happening on my new SanDisk 8gb U3 thumb drive and a new PNY 1gb
U3 thumb drive.
When inserted, Vista starts loading driver drivers for the device, but then
claims the drive is an "Unknown Device". For the external hard drive, the
driver software installation finds the WD My Book USB Device, USB Human
Interface Device, USB Mass Storage Device, USB Composite Device, and then it
fails to find "Unidentified Device". Device Manger shows the WD My Book USB
Device under disk drives, and also an Unknown device under Other devices.
Disk Management shows the drive, but without a drive letter. My computer
shows nothing for this drive.
All of these drives work fine on my older XP Pro laptop.
Please tell me why a drive letter is not being assigned to this "Unknown
Device" and how do I correct this problem.

- Michael Faklis <>

Write caching may be set wrong, and you are failing to use the "Safely
Remove Hardware" option when needed. (Device Manager, drive properties,
"Policies" tab.)

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Mark L. Ferguson

..
"Michael Faklis" <> wrote in message
news:%23n2$...
> My Vista Ultimate laptop stopped assigning driver letters to new external
> drives, whether external hard drives or thumb drives. Old thumb drives I
> used in the past are still recognized. This problem is happening on my
> new
> Western Digital 1 tb external drive, whether using USB 2 or Firewire 400.
> It is also happening on my new SanDisk 8gb U3 thumb drive and a new PNY
> 1gb
> U3 thumb drive.
> When inserted, Vista starts loading driver drivers for the device, but
> then
> claims the drive is an "Unknown Device". For the external hard drive, the
> driver software installation finds the WD My Book USB Device, USB Human
> Interface Device, USB Mass Storage Device, USB Composite Device, and then
> it
> fails to find "Unidentified Device". Device Manger shows the WD My Book
> USB
> Device under disk drives, and also an Unknown device under Other devices.
> Disk Management shows the drive, but without a drive letter. My computer
> shows nothing for this drive.
> All of these drives work fine on my older XP Pro laptop.
> Please tell me why a drive letter is not being assigned to this "Unknown
> Device" and how do I correct this problem.
>
> - Michael Faklis <>
>
>
>

Same problem here with WD external drive. I have not been able to find a
solution but I have found a pain in the ass workaround. I plug the drive
into my XP machine where it is recognized and then connect it back to the
Vista machine. Vista then recognizes it for a week or two then the cycle
starts again.

"Michael Faklis" <> wrote in message
news:%23n2$...
> My Vista Ultimate laptop stopped assigning driver letters to new external
> drives, whether external hard drives or thumb drives. Old thumb drives I
> used in the past are still recognized. This problem is happening on my
> new
> Western Digital 1 tb external drive, whether using USB 2 or Firewire 400.
> It is also happening on my new SanDisk 8gb U3 thumb drive and a new PNY
> 1gb
> U3 thumb drive.
> When inserted, Vista starts loading driver drivers for the device, but
> then
> claims the drive is an "Unknown Device". For the external hard drive, the
> driver software installation finds the WD My Book USB Device, USB Human
> Interface Device, USB Mass Storage Device, USB Composite Device, and then
> it
> fails to find "Unidentified Device". Device Manger shows the WD My Book
> USB
> Device under disk drives, and also an Unknown device under Other devices.
> Disk Management shows the drive, but without a drive letter. My computer
> shows nothing for this drive.
> All of these drives work fine on my older XP Pro laptop.
> Please tell me why a drive letter is not being assigned to this "Unknown
> Device" and how do I correct this problem.
>
> - Michael Faklis <>
>
>
>

I ALWAYS use "Safely Remove Hardware".

I keep my harddrives set to "Optimize for Performance", and thumb drives set
to "Optimize for Quick Removal". However when attaching the new drives we
never get past the driver not found for "Unknown Device" and drive letters
are not set.

- Michael Faklis


"Mark L. Ferguson" <> wrote in
message news:...
> Write caching may be set wrong, and you are failing to use the "Safely
> Remove Hardware" option when needed. (Device Manager, drive properties,
> "Policies" tab.)
>
> --
> Was this helpful? Then click the "Yes" Ratings button. Voting helps the
> web
> interface.
> http://www.microsoft.com/wn3/locales....htm#RateAPost
>
> Mark L. Ferguson
>
> .
> "Michael Faklis" <> wrote in message
> news:%23n2$...
>> My Vista Ultimate laptop stopped assigning driver letters to new external
>> drives, whether external hard drives or thumb drives. Old thumb drives I
>> used in the past are still recognized. This problem is happening on my
>> new
>> Western Digital 1 tb external drive, whether using USB 2 or Firewire 400.
>> It is also happening on my new SanDisk 8gb U3 thumb drive and a new PNY
>> 1gb
>> U3 thumb drive.
>> When inserted, Vista starts loading driver drivers for the device, but
>> then
>> claims the drive is an "Unknown Device". For the external hard drive,
>> the
>> driver software installation finds the WD My Book USB Device, USB Human
>> Interface Device, USB Mass Storage Device, USB Composite Device, and then
>> it
>> fails to find "Unidentified Device". Device Manger shows the WD My Book
>> USB
>> Device under disk drives, and also an Unknown device under Other devices.
>> Disk Management shows the drive, but without a drive letter. My computer
>> shows nothing for this drive.
>> All of these drives work fine on my older XP Pro laptop.
>> Please tell me why a drive letter is not being assigned to this "Unknown
>> Device" and how do I correct this problem.
>>
>> - Michael Faklis <>
>>
>>
>>
>

I think my problem may be corruption in the registry, where drive letters
may be assigned.

The problem started last month. Prior to that I had no problems attaching
new storage devices. Then I bought a new PNY 8gb thumb drive certified for
Vista ReadyBoost. That memory stick didn't work in Vista so I returned it
and got the SanDisk 8gb thumb drive. That didn't work either. Now new
external hard drives and thumb drives aren't assigned drive letters, and
Vista claims they are an "Unknown Device". Hard drives and thumb drives
that were in use prior to the PNY drive still work in Vista.

- Michael Faklis


"Bob" <> wrote in message
news:. ..
> Same problem here with WD external drive. I have not been able to find a
> solution but I have found a pain in the ass workaround. I plug the drive
> into my XP machine where it is recognized and then connect it back to the
> Vista machine. Vista then recognizes it for a week or two then the cycle
> starts again.
>
> "Michael Faklis" <> wrote in message
> news:%23n2$...
>> My Vista Ultimate laptop stopped assigning driver letters to new external
>> drives, whether external hard drives or thumb drives. Old thumb drives I
>> used in the past are still recognized. This problem is happening on my
>> new
>> Western Digital 1 tb external drive, whether using USB 2 or Firewire 400.
>> It is also happening on my new SanDisk 8gb U3 thumb drive and a new PNY
>> 1gb
>> U3 thumb drive.
>> When inserted, Vista starts loading driver drivers for the device, but
>> then
>> claims the drive is an "Unknown Device". For the external hard drive,
>> the
>> driver software installation finds the WD My Book USB Device, USB Human
>> Interface Device, USB Mass Storage Device, USB Composite Device, and then
>> it
>> fails to find "Unidentified Device". Device Manger shows the WD My Book
>> USB
>> Device under disk drives, and also an Unknown device under Other devices.
>> Disk Management shows the drive, but without a drive letter. My computer
>> shows nothing for this drive.
>> All of these drives work fine on my older XP Pro laptop.
>> Please tell me why a drive letter is not being assigned to this "Unknown
>> Device" and how do I correct this problem.
>>
>> - Michael Faklis <>
>>
>>
>>
>

Do you have a system restore point far enough back that could get your
registry right again if that's the problem?

"Michael Faklis" <> wrote in message
news:...
>I think my problem may be corruption in the registry, where drive letters
>may be assigned.
>
> The problem started last month. Prior to that I had no problems attaching
> new storage devices. Then I bought a new PNY 8gb thumb drive certified
> for Vista ReadyBoost. That memory stick didn't work in Vista so I
> returned it and got the SanDisk 8gb thumb drive. That didn't work either.
> Now new external hard drives and thumb drives aren't assigned drive
> letters, and Vista claims they are an "Unknown Device". Hard drives and
> thumb drives that were in use prior to the PNY drive still work in Vista.
>
> - Michael Faklis
>
>
> "Bob" <> wrote in message
> news:. ..
>> Same problem here with WD external drive. I have not been able to find a
>> solution but I have found a pain in the ass workaround. I plug the drive
>> into my XP machine where it is recognized and then connect it back to the
>> Vista machine. Vista then recognizes it for a week or two then the cycle
>> starts again.
>>
>> "Michael Faklis" <> wrote in message
>> news:%23n2$...
>>> My Vista Ultimate laptop stopped assigning driver letters to new
>>> external
>>> drives, whether external hard drives or thumb drives. Old thumb drives
>>> I
>>> used in the past are still recognized. This problem is happening on my
>>> new
>>> Western Digital 1 tb external drive, whether using USB 2 or Firewire
>>> 400.
>>> It is also happening on my new SanDisk 8gb U3 thumb drive and a new PNY
>>> 1gb
>>> U3 thumb drive.
>>> When inserted, Vista starts loading driver drivers for the device, but
>>> then
>>> claims the drive is an "Unknown Device". For the external hard drive,
>>> the
>>> driver software installation finds the WD My Book USB Device, USB Human
>>> Interface Device, USB Mass Storage Device, USB Composite Device, and
>>> then it
>>> fails to find "Unidentified Device". Device Manger shows the WD My Book
>>> USB
>>> Device under disk drives, and also an Unknown device under Other
>>> devices.
>>> Disk Management shows the drive, but without a drive letter. My computer
>>> shows nothing for this drive.
>>> All of these drives work fine on my older XP Pro laptop.
>>> Please tell me why a drive letter is not being assigned to this "Unknown
>>> Device" and how do I correct this problem.
>>>
>>> - Michael Faklis <>
>>>
>>>
>>>
>>
>
>

Ventured back into the pit again, Colin :-)


"Colin Barnhorst" <> wrote in message
news:576D3F19-ACB1-4914-9509-...
> Do you have a system restore point far enough back that could get your
> registry right again if that's the problem?
>
> "Michael Faklis" <> wrote in message
> news:...
>>I think my problem may be corruption in the registry, where drive letters
>>may be assigned.
>>
>> The problem started last month. Prior to that I had no problems
>> attaching new storage devices. Then I bought a new PNY 8gb thumb drive
>> certified for Vista ReadyBoost. That memory stick didn't work in Vista
>> so I returned it and got the SanDisk 8gb thumb drive. That didn't work
>> either. Now new external hard drives and thumb drives aren't assigned
>> drive letters, and Vista claims they are an "Unknown Device". Hard
>> drives and thumb drives that were in use prior to the PNY drive still
>> work in Vista.
>>
>> - Michael Faklis
>>
>>
>> "Bob" <> wrote in message
>> news:. ..
>>> Same problem here with WD external drive. I have not been able to find a
>>> solution but I have found a pain in the ass workaround. I plug the drive
>>> into my XP machine where it is recognized and then connect it back to
>>> the Vista machine. Vista then recognizes it for a week or two then the
>>> cycle starts again.
>>>
>>> "Michael Faklis" <> wrote in message
>>> news:%23n2$...
>>>> My Vista Ultimate laptop stopped assigning driver letters to new
>>>> external
>>>> drives, whether external hard drives or thumb drives. Old thumb drives
>>>> I
>>>> used in the past are still recognized. This problem is happening on my
>>>> new
>>>> Western Digital 1 tb external drive, whether using USB 2 or Firewire
>>>> 400.
>>>> It is also happening on my new SanDisk 8gb U3 thumb drive and a new PNY
>>>> 1gb
>>>> U3 thumb drive.
>>>> When inserted, Vista starts loading driver drivers for the device, but
>>>> then
>>>> claims the drive is an "Unknown Device". For the external hard drive,
>>>> the
>>>> driver software installation finds the WD My Book USB Device, USB Human
>>>> Interface Device, USB Mass Storage Device, USB Composite Device, and
>>>> then it
>>>> fails to find "Unidentified Device". Device Manger shows the WD My
>>>> Book USB
>>>> Device under disk drives, and also an Unknown device under Other
>>>> devices.
>>>> Disk Management shows the drive, but without a drive letter. My
>>>> computer
>>>> shows nothing for this drive.
>>>> All of these drives work fine on my older XP Pro laptop.
>>>> Please tell me why a drive letter is not being assigned to this
>>>> "Unknown
>>>> Device" and how do I correct this problem.
>>>>
>>>> - Michael Faklis <>
>>>>
>>>>
>>>>
>>>
>>
>>
>

Been here for about three months, John. But not in vista.general. No way.

"John Barnes" <> wrote in message
news:uU%...
> Ventured back into the pit again, Colin :-)
>
>
> "Colin Barnhorst" <> wrote in message
> news:576D3F19-ACB1-4914-9509-...
>> Do you have a system restore point far enough back that could get your
>> registry right again if that's the problem?
>>
>> "Michael Faklis" <> wrote in message
>> news:...
>>>I think my problem may be corruption in the registry, where drive letters
>>>may be assigned.
>>>
>>> The problem started last month. Prior to that I had no problems
>>> attaching new storage devices. Then I bought a new PNY 8gb thumb drive
>>> certified for Vista ReadyBoost. That memory stick didn't work in Vista
>>> so I returned it and got the SanDisk 8gb thumb drive. That didn't work
>>> either. Now new external hard drives and thumb drives aren't assigned
>>> drive letters, and Vista claims they are an "Unknown Device". Hard
>>> drives and thumb drives that were in use prior to the PNY drive still
>>> work in Vista.
>>>
>>> - Michael Faklis
>>>
>>>
>>> "Bob" <> wrote in message
>>> news:. ..
>>>> Same problem here with WD external drive. I have not been able to find
>>>> a solution but I have found a pain in the ass workaround. I plug the
>>>> drive into my XP machine where it is recognized and then connect it
>>>> back to the Vista machine. Vista then recognizes it for a week or two
>>>> then the cycle starts again.
>>>>
>>>> "Michael Faklis" <> wrote in message
>>>> news:%23n2$...
>>>>> My Vista Ultimate laptop stopped assigning driver letters to new
>>>>> external
>>>>> drives, whether external hard drives or thumb drives. Old thumb
>>>>> drives I
>>>>> used in the past are still recognized. This problem is happening on
>>>>> my new
>>>>> Western Digital 1 tb external drive, whether using USB 2 or Firewire
>>>>> 400.
>>>>> It is also happening on my new SanDisk 8gb U3 thumb drive and a new
>>>>> PNY 1gb
>>>>> U3 thumb drive.
>>>>> When inserted, Vista starts loading driver drivers for the device, but
>>>>> then
>>>>> claims the drive is an "Unknown Device". For the external hard drive,
>>>>> the
>>>>> driver software installation finds the WD My Book USB Device, USB
>>>>> Human
>>>>> Interface Device, USB Mass Storage Device, USB Composite Device, and
>>>>> then it
>>>>> fails to find "Unidentified Device". Device Manger shows the WD My
>>>>> Book USB
>>>>> Device under disk drives, and also an Unknown device under Other
>>>>> devices.
>>>>> Disk Management shows the drive, but without a drive letter. My
>>>>> computer
>>>>> shows nothing for this drive.
>>>>> All of these drives work fine on my older XP Pro laptop.
>>>>> Please tell me why a drive letter is not being assigned to this
>>>>> "Unknown
>>>>> Device" and how do I correct this problem.
>>>>>
>>>>> - Michael Faklis <>
>>>>>
>>>>>
>>>>>
>>>>
>>>
>>>
>>
>

I see. This is cross posted to general, too.

"Colin Barnhorst" <> wrote in message
news:7D92C9BD-853A-41E2-A138-...
> Been here for about three months, John. But not in vista.general. No
> way.
>
> "John Barnes" <> wrote in message
> news:uU%...
>> Ventured back into the pit again, Colin :-)
>>
>>
>> "Colin Barnhorst" <> wrote in message
>> news:576D3F19-ACB1-4914-9509-...
>>> Do you have a system restore point far enough back that could get your
>>> registry right again if that's the problem?
>>>
>>> "Michael Faklis" <> wrote in message
>>> news:...
>>>>I think my problem may be corruption in the registry, where drive
>>>>letters may be assigned.
>>>>
>>>> The problem started last month. Prior to that I had no problems
>>>> attaching new storage devices. Then I bought a new PNY 8gb thumb drive
>>>> certified for Vista ReadyBoost. That memory stick didn't work in Vista
>>>> so I returned it and got the SanDisk 8gb thumb drive. That didn't work
>>>> either. Now new external hard drives and thumb drives aren't assigned
>>>> drive letters, and Vista claims they are an "Unknown Device". Hard
>>>> drives and thumb drives that were in use prior to the PNY drive still
>>>> work in Vista.
>>>>
>>>> - Michael Faklis
>>>>
>>>>
>>>> "Bob" <> wrote in message
>>>> news:. ..
>>>>> Same problem here with WD external drive. I have not been able to find
>>>>> a solution but I have found a pain in the ass workaround. I plug the
>>>>> drive into my XP machine where it is recognized and then connect it
>>>>> back to the Vista machine. Vista then recognizes it for a week or two
>>>>> then the cycle starts again.
>>>>>
>>>>> "Michael Faklis" <> wrote in message
>>>>> news:%23n2$...
>>>>>> My Vista Ultimate laptop stopped assigning driver letters to new
>>>>>> external
>>>>>> drives, whether external hard drives or thumb drives. Old thumb
>>>>>> drives I
>>>>>> used in the past are still recognized. This problem is happening on
>>>>>> my new
>>>>>> Western Digital 1 tb external drive, whether using USB 2 or Firewire
>>>>>> 400.
>>>>>> It is also happening on my new SanDisk 8gb U3 thumb drive and a new
>>>>>> PNY 1gb
>>>>>> U3 thumb drive.
>>>>>> When inserted, Vista starts loading driver drivers for the device,
>>>>>> but then
>>>>>> claims the drive is an "Unknown Device". For the external hard
>>>>>> drive, the
>>>>>> driver software installation finds the WD My Book USB Device, USB
>>>>>> Human
>>>>>> Interface Device, USB Mass Storage Device, USB Composite Device, and
>>>>>> then it
>>>>>> fails to find "Unidentified Device". Device Manger shows the WD My
>>>>>> Book USB
>>>>>> Device under disk drives, and also an Unknown device under Other
>>>>>> devices.
>>>>>> Disk Management shows the drive, but without a drive letter. My
>>>>>> computer
>>>>>> shows nothing for this drive.
>>>>>> All of these drives work fine on my older XP Pro laptop.
>>>>>> Please tell me why a drive letter is not being assigned to this
>>>>>> "Unknown
>>>>>> Device" and how do I correct this problem.
>>>>>>
>>>>>> - Michael Faklis <>
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>
>>>>
>>>
>>
>

I am having similar issues with a new computer, now running Vista Home
Premium. My USB external drives are not installing properly and are coming
up "unknown device". They do not appear in disk management at all, and are
not recognized anywhere as mass storage devices. I have tried uninstalling
the USB drivers and reinstalling them, removing infcache.1, numerous
reboots... I no longer have an XP computer to access the information on
these drives. Help please? Anyone??

"John Barnes" wrote:

> I see. This is cross posted to general, too.
>
> "Colin Barnhorst" <> wrote in message
> news:7D92C9BD-853A-41E2-A138-...
> > Been here for about three months, John. But not in vista.general. No
> > way.
> >
> > "John Barnes" <> wrote in message
> > news:uU%...
> >> Ventured back into the pit again, Colin :-)
> >>
> >>
> >> "Colin Barnhorst" <> wrote in message
> >> news:576D3F19-ACB1-4914-9509-...
> >>> Do you have a system restore point far enough back that could get your
> >>> registry right again if that's the problem?
> >>>
> >>> "Michael Faklis" <> wrote in message
> >>> news:...
> >>>>I think my problem may be corruption in the registry, where drive
> >>>>letters may be assigned.
> >>>>
> >>>> The problem started last month. Prior to that I had no problems
> >>>> attaching new storage devices. Then I bought a new PNY 8gb thumb drive
> >>>> certified for Vista ReadyBoost. That memory stick didn't work in Vista
> >>>> so I returned it and got the SanDisk 8gb thumb drive. That didn't work
> >>>> either. Now new external hard drives and thumb drives aren't assigned
> >>>> drive letters, and Vista claims they are an "Unknown Device". Hard
> >>>> drives and thumb drives that were in use prior to the PNY drive still
> >>>> work in Vista.
> >>>>
> >>>> - Michael Faklis
> >>>>
> >>>>
> >>>> "Bob" <> wrote in message
> >>>> news:. ..
> >>>>> Same problem here with WD external drive. I have not been able to find
> >>>>> a solution but I have found a pain in the ass workaround. I plug the
> >>>>> drive into my XP machine where it is recognized and then connect it
> >>>>> back to the Vista machine. Vista then recognizes it for a week or two
> >>>>> then the cycle starts again.
> >>>>>
> >>>>> "Michael Faklis" <> wrote in message
> >>>>> news:%23n2$...
> >>>>>> My Vista Ultimate laptop stopped assigning driver letters to new
> >>>>>> external
> >>>>>> drives, whether external hard drives or thumb drives. Old thumb
> >>>>>> drives I
> >>>>>> used in the past are still recognized. This problem is happening on
> >>>>>> my new
> >>>>>> Western Digital 1 tb external drive, whether using USB 2 or Firewire
> >>>>>> 400.
> >>>>>> It is also happening on my new SanDisk 8gb U3 thumb drive and a new
> >>>>>> PNY 1gb
> >>>>>> U3 thumb drive.
> >>>>>> When inserted, Vista starts loading driver drivers for the device,
> >>>>>> but then
> >>>>>> claims the drive is an "Unknown Device". For the external hard
> >>>>>> drive, the
> >>>>>> driver software installation finds the WD My Book USB Device, USB
> >>>>>> Human
> >>>>>> Interface Device, USB Mass Storage Device, USB Composite Device, and
> >>>>>> then it
> >>>>>> fails to find "Unidentified Device". Device Manger shows the WD My
> >>>>>> Book USB
> >>>>>> Device under disk drives, and also an Unknown device under Other
> >>>>>> devices.
> >>>>>> Disk Management shows the drive, but without a drive letter. My
> >>>>>> computer
> >>>>>> shows nothing for this drive.
> >>>>>> All of these drives work fine on my older XP Pro laptop.
> >>>>>> Please tell me why a drive letter is not being assigned to this
> >>>>>> "Unknown
> >>>>>> Device" and how do I correct this problem.
> >>>>>>
> >>>>>> - Michael Faklis <>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>
> >>>>
> >>>>
> >>>
> >>
> >
>
>