I have 2 USB external drives (Amacom IODisk) of different sizes. Separately
both work well (with different drive letters) but if I try to plug them both
in XP Pro only sees one of them. If I start up or shut down with both
plugged in, Windows hangs until I remove one of them. There are no errors in
Device Manager.

Please could someone tell me how can I get Windows to see both drives at the
same time?

I am not aware of any restriction in XP, so one should attempt to plug the
drive into different USB controllers.

Some PCs only have 2 USB ports and other 4 or more. If you have 4 or more
just moove the Hard drive to other ports and see if it is recognised.

"sm" wrote:

> I have 2 USB external drives (Amacom IODisk) of different sizes. Separately
> both work well (with different drive letters) but if I try to plug them both
> in XP Pro only sees one of them. If I start up or shut down with both
> plugged in, Windows hangs until I remove one of them. There are no errors in
> Device Manager.
>
> Please could someone tell me how can I get Windows to see both drives at the
> same time?
>
>
>

This can be a conflict over drive letter assignment. The winner gets the letter,
the other drive is invisible.
To resolve this, open Disk manager (in Computer management)
and check assignment of driver letters.
--PA

"sm" <(E-Mail Removed)> wrote in message news:(E-Mail Removed)...
> I have 2 USB external drives (Amacom IODisk) of different sizes. Separately
> both work well (with different drive letters) but if I try to plug them both
> in XP Pro only sees one of them. If I start up or shut down with both
> plugged in, Windows hangs until I remove one of them. There are no errors in
> Device Manager.
>
> Please could someone tell me how can I get Windows to see both drives at the
> same time?
>
>

Thanks for that. I have tried different USB ports and have ensured that the
drives get different drive letters but it still doesn't work! I am
mystified.

Try going into the registry, remove the key for both devices, reboot,
and plug them in one at a time. Here is how to do the registry part:

Disconnect the problem device and open the Registry Editor
(Start-Run-regedit). Navigate to HKLM\System\CCS\Enum\USB and look for
the folder containing information about the problematic device. Now
right click on the folder labeled Vid_Xxxx that contains the information
about the problematic device and click Permission. Allow full control
of the key, then right click on it and delete it. Now reboot and try
again.

-----
Nathan McNulty

sm wrote:
> Thanks for that. I have tried different USB ports and have ensured that the
> drives get different drive letters but it still doesn't work! I am
> mystified.
>
>

"Nathan McNulty" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Try going into the registry, remove the key for both devices, reboot, and
> plug them in one at a time. Here is how to do the registry part:
>
> Disconnect the problem device and open the Registry Editor
> (Start-Run-regedit). Navigate to HKLM\System\CCS\Enum\USB and look for
> the folder containing information about the problematic device. Now right
> click on the folder labeled Vid_Xxxx that contains the information about
> the problematic device and click Permission. Allow full control of the
> key, then right click on it and delete it. Now reboot and try again.
>

A preliminary look doesn't find anything that identifies the drives, though
it is hard to be sure. They do appear in HKLM\System\CCS\Enum\USBSTOR in the
Disk&Ven_xxx folders.

I'll keep looking to see if there's anything in the Disk&Ven_xxx folders to
show which Vid_Xxxx is relevant

I'm afraid that I can't find anything in a Vid_Xxxx folder that contains
information about either of the drives. So now what?

Have you only tried to use the on-board USB ports?

Maybe you should try a powered USB hub? It could be that the USB signals
become weak with the two drives installed?


"sm" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
>I have 2 USB external drives (Amacom IODisk) of different sizes. Separately
>both work well (with different drive letters) but if I try to plug them
>both in XP Pro only sees one of them. If I start up or shut down with both
>plugged in, Windows hangs until I remove one of them. There are no errors
>in Device Manager.
>
> Please could someone tell me how can I get Windows to see both drives at
> the same time?
>

"Yves Leclerc" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Have you only tried to use the on-board USB ports?
>
> Maybe you should try a powered USB hub? It could be that the USB signals
> become weak with the two drives installed?

Yes I am using a powered USB hub. I even tried the optional extra cable that
comes with the drive which provides power from another USB port.

If the drives are firewire/usb buying a cheap firewire/USB2 card on eBa
might provide a fast solution.


sm Wrote:
> "Yves Leclerc" (E-Mail Removed) wrote in message
> news:(E-Mail Removed)...-
> Have you only tried to use the on-board USB ports?
>
> Maybe you should try a powered USB hub? It could be that the US
> signals
> become weak with the two drives installed?-
>
> Yes I am using a powered USB hub. I even tried the optional extra cabl
> that
> comes with the drive which provides power from another USB port

--
Georgef