Thanks for your help guys but it is not drivers or any such thing...
I found the answer, and here is a first, in Windows own Help files...
Foreign
For instructions describing how to fix disks with Foreign status, see Troubleshooting.
The Foreign status occurs when you move a dynamic disk to a local computer running Windows XP Home Edition from another computer running Windows 2000, or Windows XP Professional. The Foreign status can also occur on computers running Windows XP Home Edition that are configured to dual-boot with another operating system that uses dynamic disks (such as Windows 2000 Professional). Dynamic disks are not supported on Windows XP Home Edition or on portable computers. A warning icon appears on disks that display the Foreign status.
You cannot access data on the disk, but you can convert the disk to a basic disk so that you can use it with Windows XP Home Edition.
Warning
Converting a dynamic disk to a basic disk destroys all data on the disk. Do not convert a dynamic disk to a basic disk unless you are certain that you no longer need the data on that disk.
To convert the disk to an empty basic disk, right-click the disk, and then click Convert to Basic Disk.
The old machine was running XP pro, I was cheap and just went for home edition on the laptop. Who knew you couldn't swap drives between them? That seems pretty dumb.
So all I have to do is plug the drive back into the desktop, copy the data off it, reformat the drive (or change it to basic rather than dynamic!? ) with diskmangement while conncted to the laptop and copy the data back. Thank you Microsoft!
Better yet, I can use dskprobe to change from dynamic to basic disc.
http://thelazyadmin.net/index.php?/a...sic-Disks.html
http://faq.arstechnica.com/link.php?i=1806
Of course I will still have to put the drive back in the old system to do that but at least I won't have to copy 70G+ of data twice!
Let you know how it goes tomorrow...