I have been grappling with my main OS recently, (attempt at upgrade didn't go, restored from backup, and then fought for printing). VirtualBox starts & runs, but it's showing an outdated list of VMs. In virtualbox, I see Vista & Fedora 22. But I have on disk Vista (The same Vista), Linux Mint-18.1, & Windows 10. Windows 10 is (as always) expendable, but I actually need the Linux Mint install

I also have a backup of most things from before I started messing, so the correct file(s) is/are there for me - if I knew what they were. Needless to say, after such a struggle, I don't want to do anything 'nuclear' in the way of restoring files, but I can do something targeted. VB is on /opt which was not really involved in my recent issues.

Any help appreciated

Sorted this.

I completely failed to find instructions on this, but managed almost by accident. In VirtualBox, select 'machine/add.' The menu took me to my /mnt/virtual partition where my VMs all live. Select the <machine>.vbox file and you're done. Repeat for all missing machines.