Have copied .vdi file, now primary in VM inaccessible

[Graham@JMD]

I've copied the .vdi file for a Windows XP VM to a flash drive (in the host OS, Windows 8) to create a copy of the VM on a separate host, when restarted VirtualBox got an error that primary drive inaccessible. Restored from snapshot taken immediately before .vdi file copied, no luck.
Can someone please advise how copying the .vdi file in the host OS affects VirtualBox, and how do I fix it?
*edit - VirtualBox version is 4.3.12

[mpack]

Howto: Move a VM.

[scottgus1]

Theoretically, simply copying a vdi should not affect the source vdi. I do that for backups of my guests all the time (simple drag-n-drop or command-line copying) and have no problems. Did you possibly "Move" instead of "Copy" without noticing it? In other words - simple question here but it needs to be asked, just to cover all bases - Is your source vdi still in the folder it was in before you copied?

If it is (of course it is, right? ) I'd look harder at that snapshot thingy you say you did right before the copy. Maybe that didn't work right? Experts on the forum say snapshots, although offered, make the guests more delicate.

Maybe posting the items requested here: viewtopic.php?f=24&t=48476 might help.

[mpack]

@Scottgus: I think the OP is saying that he moved a VM by copying the bare VDI to another host. Then he mentioned that snapshots are involved too, which obviously opens up a whole Pandora's box of potential trouble. Better that the OP retraces his steps and does the VM move correctly.

[scottgus1]

Could be, Mpack. I got the impression that he "restarted" Virtualbox on the source PC and had the problem there after the copy. Perhaps Graham could give an essential piece of info then: Which computer does the error happen on, the old one or the new one?

[mpack]

And another piece of essential info: how did he alter the path to the VDI? Obviously, unregistering the base VDI and then mounting the base VDI in a VM which was using snapshots... hardly bears thinking about. Total FUBAR.