USB Problem

  • Thread starter Thread starter Michael C
  • Start date Start date
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Michael C

I purchased a 5 metre USB 2.0 extension cable for my PC. This is an active
cable that has a circuit in it to repeat the signal, so it should be
detected as a USB hub even if it has nothing plugged into the end of it. But
for some reason it keeps coming up as "Unknown Device" on one PC. I've tried
the cable on 3 other machines and it works perfectly on them but I've also
tried 5 other usb devices on the computer and they all worked perfectly. The
computer is a brand new p4 3.2 with winXP pro SP2, it hardly has any
programs installed on it and nothing unusual about it except for a PCI
capture card.

What I think has happened is that the first time I plugged the cable into
the PC I might not have pushed it in all the way and it disconnected during
the install causing the default driver to not load correctly. So from then
on it installed as Unknown device. I can't change the drivers because it
doesn't come with any and windows me assign any other built in drivers. I've
removed it from device manager but it keeps coming back as Unknown Device.
Is there any way to remove all knowledge of this cable from the registry and
install it fresh?

If you've got this far thanks for looking,
Michael
 
Have you checked the Restore Points before installation of of the cable?
Additionally, if the computer is so new you could do a reinstallation of the
OS and see if that doesn't correct the problem.
 
I purchased a 5 metre USB 2.0 extension cable for my PC. This is an active
cable that has a circuit in it to repeat the signal, so it should be
detected as a USB hub even if it has nothing plugged into the end of it. But
for some reason it keeps coming up as "Unknown Device" on one PC. I've tried
the cable on 3 other machines and it works perfectly on them but I've also
tried 5 other usb devices on the computer and they all worked perfectly. The
computer is a brand new p4 3.2 with winXP pro SP2, it hardly has any
programs installed on it and nothing unusual about it except for a PCI
capture card.

What I think has happened is that the first time I plugged the cable into
the PC I might not have pushed it in all the way and it disconnected during
the install causing the default driver to not load correctly. So from then
on it installed as Unknown device. I can't change the drivers because it
doesn't come with any and windows me assign any other built in drivers. I've
removed it from device manager but it keeps coming back as Unknown Device.
Is there any way to remove all knowledge of this cable from the registry and
install it fresh?
Click to expand...


Yes, but I don't remember the registry key. Look around in
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum , "maybe"
in a USB subkey, or maybe not (I don't have an ME box
running at the moment). It may be displayed as only a
device ID number, that is, you could have multiple unknown
devices. One way to differentiate them is to go into Device
Manager and manually assign the "wrong" driver/device for
it. ie- just pick something in the manual device selection
of the wizard that it definitely is NOT, to be able to
distinguish it when searching.

Once you find the device ID string (hex), copy it and search
whole registry for it. If it describes a device class
elswhere rather than a detected device, do not delete the
device class registry entries, only the instances of it
being detected. Unfortunately my memory of WinME registry
is dated and I can't be 100% certain of the particular keys
to give specific advice other than this vague idea about not
deleting device classes rather than enumerated hardware.

The aforementioned assigning-wrong-device manually can also
sometimes be useful to resolve such problems by then
installing the driver while the cable is unplugged (after
rebooting), THEN plugging in the cable. It may not be that
simple, sometimes it's a quirky combination of steps in a
particular order to get it working.
 
kony said:
Yes, but I don't remember the registry key. Look around in
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum , "maybe"
in a USB subkey, or maybe not (I don't have an ME box
running at the moment). It may be displayed as only a
device ID number, that is, you could have multiple unknown
devices. One way to differentiate them is to go into Device
Manager and manually assign the "wrong" driver/device for
it. ie- just pick something in the manual device selection
of the wizard that it definitely is NOT, to be able to
distinguish it when searching.

Once you find the device ID string (hex), copy it and search
whole registry for it. If it describes a device class
elswhere rather than a detected device, do not delete the
device class registry entries, only the instances of it
being detected. Unfortunately my memory of WinME registry
is dated and I can't be 100% certain of the particular keys
to give specific advice other than this vague idea about not
deleting device classes rather than enumerated hardware.

The aforementioned assigning-wrong-device manually can also
sometimes be useful to resolve such problems by then
installing the driver while the cable is unplugged (after
rebooting), THEN plugging in the cable. It may not be that
simple, sometimes it's a quirky combination of steps in a
particular order to get it working.
Click to expand...

Hi Kony,

Thanks for the reply. The PC has WinXP Pro installed on it, not ME. Does
that change anything?

Michael
 
Jan Alter said:
Have you checked the Restore Points before installation of of the cable?
Click to expand...

Not as yet, it seemed a bit of overkill.
Additionally, if the computer is so new you could do a reinstallation of
the OS and see if that doesn't correct the problem.
Click to expand...

That might be an option but after I've tried everything else.

Michael
 
Hi Kony,

Thanks for the reply. The PC has WinXP Pro installed on it, not ME. Does
that change anything?
Click to expand...


LOL. Yes you did pretty plainly state that it was running
XP, I think I had other things on my mind and just glanced
up to read "doesn't come with any and windows me assign..."

Anyway, it doesn't change much, though it may make it more
likely others would (now) know which particular USB hub
entries it "should" have rather than "unknown device"... but
we still can't help you determine the specific device ID
string unless someone out there just happened to have the
exact same cable.

Had you previously tried selecting this "unknown device" in
Device Manager, choosing to manually select a driver for it
then setting it as type "USB HUB" (or whatever option seems
most closely related, I dont' recall at the moment "all" the
possible manual hardware category labels).

However, since you have it working on the other PCs, that
might be helpful. Similar to described previously if you
search and export the related registry entries for that
device on another WinXP PC (one on which it works properly),
plus delete those on the non-working PC, then add the
exported reg entries to the non-working pc (and possibly
reboot), that might do the trick.
 
kony said:
However, since you have it working on the other PCs, that
might be helpful. Similar to described previously if you
search and export the related registry entries for that
device on another WinXP PC (one on which it works properly),
plus delete those on the non-working PC, then add the
exported reg entries to the non-working pc (and possibly
reboot), that might do the trick.
Click to expand...

This did work, I went through the registry and found all of the entries for
Unknown Device and deleted them. Strangely it came up as unknown device
again but when I unplugged it and plugged it back in it detected correctly.
I re-plugged (is that a word?) it several times again after that and did a
couple of reboots and it worked every time. Previously I had got it to work
a couple of times on this PC but it always failed immediately if I
re-plugged it so I'm confident the problem's fixed.

The odd thing with XP was I could find no way to get XP to even attempt to
accept another driver without having drivers on disk. I tried every
combination of autosearch, specify location, specify C:\windows\inf as a
location etc etc and it would only ever come up with Unknown Device as a
possibility.

Thanks for your help,
Michael
 
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