Hi everyone,

I've got two identical spec SBS2003 Dell Poweredge 2950's. One is my domain controller and exchange server the other is just a CCTV server.

When I plug a WD Elements 1.5tb external drive into the CCTV server it pops up and installs no prob. When I plug that same drive into my domain controller nothing happens. I did see something pop up with "unrecognized device" after a reboot.

I'd like to use this 1.5TB drive for backup instead of the current 500gb WD Elements drive currently plugged in.

Is there something in the registry that could be causing problems?


I do remember unplugging my 500gb once and when I plugged it back in it wouldn't recognize it either and that sent me reading for days...

What is device manager telling you about the device when plugged into the problem server. Post the error/status code in device manager - exclamation mark on the device.

This is the SAME physical drive you are using between the two servers or different, but identical drives?

Thanks for the quick reply, G!

Well I had a look around for a status code but couldn't find anything.

In Device Manager it shows up in the list of USB devices as "Unknown Device"

I already have another ext USB drive (my current backup) plugged in and working. I can see that in Device Manager below my SCSI drives as WD 5000AAK External USB Device.

The two drives are in the same WD Elements housing but one is a 500GB and the other (non working) is a 1.5TB.

I was begining to think the 1.5TB wasn't compatible but after the other SBS server recognized and installed the driver without any problems I figured the could be a simple explanation why this OS doesn't like it.....

But there definitely hasn't been any simple explanations so far :(

To clarify, you have one existing backup drive attached and working. Then you have two additional drives in another/same enclosure (500GB & 1.5TB)?

Explain how you came to get this setup - do they share a common usb cable? Confusing.

When you attach the two drives in the same enclosure to the other server it works - correct?

I have a 500gb drive in one usb port performing my backups... but it's too small. I'd like to plug a second drive into a second USB port and once I know it's working I would unplug the 500gb and keep it for a spare and just leave the 1.5TB

I have 4 USB ports. 1 is being used by the 500gb backup drive, 1 is being used by the 1.5TB drive (but isn't being recognized), 1 has my mouse and the last has my keyboard.

I'd like to unplug the 500GB but last time I unplugged that drive SBS gave me some trouble recognizing it again. That's the only reason I'd have two USB drives running at the same time. It would only be until I was confident the 1.5TB was ready to take over the backup duties.

Sorry about the confusion.

Just for kicks, why don't you go into device manager and delete the existing 500GB drive and the 1.5TB unrecognized device. Then use the "safely remove usb device" button on the taskbar (in case either device is still listed - doubtful) and unplug both USB cables from the server.

* Do a CCleaner temp file cleanup. Follow that with a CCleaner Registry cleaning (running until no more errors are found and SAVING a backup before fixing errors each time).
* Reboot server
* Plug in the 1.5TB drive and see what happens in DevMgr & in Disk Management.
* If no joy, plug in old 500GB hard drive

Warning: There is some possibility that the 500GB drive will NOT be recognized. Probably small, but you know how things roll - down hill. As an unpaid consultant, I still have to point out the risks. I wouldn't worry a bit about the CCleaner activities. I've done this before with numerous Server 2003/SBS 2003.

In case the above doesn't work, I have had some success with this software:

http://bytesolutions.com/Support/Knowledgebase/KB_...

Basically, it removes all the phantom drives that the server is never likely to see / use again. It might be that you've got so many phantom devices that the server is having issue allocating another device. The reason for this might be that the backup software (can't be specific as I don't know which software package you are using) is creating and mounting virtual images which can lead to a massive amount of phantom drives. If you have a working backup at the moment, however, make sure that you did that before running the DevNodeClean /R just in case it causes issues (although it never has for me).

Thanks for the replies guys.

Well I'm still having the same problem. There seems to be 100s of people with the same issues. I've read some pretty extreme ideas to fix it.

Goom - I'm afraid! I don't want to delete the old drive because that's my only backup... and if it spits that drive out I'm in big trouble.

Magzy - I read through your site. Thanks for that. I'm a little nervous trying some of that stuff, too.

I've tried a few different drives now with the same results... it doesn't look like it's a prob with the WD Elements disk. The other drives pop up as "unknown device" and fail to load drivers.

Some people say to reboot with no external drives plugged. One booted I can try a different USB port to at least get it to recognize there's a new device plugged in. I don't have easy access to other ports though...

Oh well. I guess I should just keep reading.

Try a powered external USB hub and see if that does it. That will connect it to a different USB root hub than the built-in one. It is one of the rotten problems that doesn't have a general fix.

Server reload will surely fix it.