VirtualBox re-install

[Photon]

I have a Linux guest on a Windows host. Recently my Windows crashed and required a complete reinstall.
After installing everything, I created a new VirtualBox Linux machine and used the pre-existing .vdi disk, but no matter what settings I use, the guest refuses to start, and sits there in a black window, doing nothing.

Any ideas?

[mpack]

That is not how you move a VM.

How to move a VM.

[scottgus1]

The essential part of the link Mpack posted is this: provided your entire guest folder, with the vdi file and all the other files that made up that guest, are in exactly the same place they were on the old OS, drive letters, etc. all the same, all you have to do after successfully re-installing Virtualbox on your new OS is double-click the .vbox file in the guest folder. The guest will register with the new install of Virtualbox and start right up again.

If you moved the guest folder to another hard drive, without changing the locations of anything in the guest folder, so you could format your OS drive, you can just put it back anywhere your convenience wants it, then double-click the .vbox file in the guest folder to register the guest.

[Photon]

The machine folder was lost with the windows OS drive, and the .vdi was on another drive which survived.
I assumed it would work, as the virtual drive is like a disk drive that you can move to an identical machine and start.

Given that I don't have the folder, is there something to do, or do I have to create a new machine, and mount the old drive to salvage data?

[scottgus1]

It is possible to just use a vdi file all by itself in a new guest. The key is the "identical" part. You will have to re-build the guest's settings as close as possible to the original settings. There are some settings that may not matter as much if they're different, like the amount of memory or the number of monitors. Other settings are essential to get right for the guest to boot up again. A usual killer for Windows guests is whether IO-APIC was on or not. Linux users may be able to suggest a setting or two for you to toggle. Suggestion if you don't get more activity here, try posting in "Linux guests" under a subject like "Help rebuild Linux (insert flavor) guest with no vbox only vdi" or something like that.

Try to match the guest type and flavor to the OS installed in the guest as best as you can remember. If you weren't much of a tinkerer when you set up this guest, you may have just left the default settings in place. Otherwise, just start with a fresh guest and attach this vdi as a second drive to get data files off it.

This kind of issue demonstrates a good reason to keep all the guest files in one place, in the guest folder, and make backups of the guest folder and all the files therein. Having the guest folder on a different drive is ok, but keep all the files together if at all possible until experience is gained.