import foreign dynamic disk created in Windows Server 2008 R2 to Windows Server 2003

Yes you can. But by span - do you mean that you are going to connect several drives?

Yes, I am moving 3 drives that contain dynamic spanned volume. When I attach them to the Server 2003 they show up as foreign disks in Disk Manager. When I attempt to import them I get the error "INTERNAL Error - The disk group contains no valid configuration copies  (C10000B6)".
When I move them back to Server 2008 R2 they come up without problems.

The only mention I found about compatibility of dynamic disks between operating systems was here:
quote: "Dynamic disks created in Windows 2008 Server are not recognized in prior versions"
http://www.diskinternals.com/raid/
Now trying to find out if that's true.

Is there an official statement from Microsoft (in a manual or KB) that says that dynamic spanned volumes created in Server 2008 R2 are not backwards compatible with Server 2003?
I have to prove to myself and my client that I am not crazy. And the only option is to copy several TBs of data. Twice.

Looks like I was not correct with my reference to the fact that spanned dynamic drives cannot be moved. Do you have any dynamic drive on 2003 machine?
If yes then Microsoft marks it as the reason you cannot move to it dynamic drives from another machine.
Here they say that moving is possible for spanned drives but you must to connect all the drives on span at the same time to target machine and then scan the drives in Windows  Disk Management. Then import them.
http://support.microsoft.com/kb/222189/

I am certainly attaching all three at the same time. But like I said they don't import. And there are no other dynamic disks in Server 2003. There used to be though. I'll try deleting dynamic disk group before import.
Oh, and I don't know what you mean by "scan the drives in Disk Management".

There is an option in Windows Disk Management - Action - Rescan Disks.
And yes, removing different group could do the trick. Be sure that you dynamic drives are not connected to this machine when you remove it.

solution selected by moderator is not correct

the partially accurate solution is #33798423

The solution given was a good guess with no backup from reputable sources.
My last comments were based on practical tests.