Is there a way to recover VM's in their entirety to another drive?

[OldChap]

Background:
New user attempting to get files on host to be movable to vm and in the process, probably having left a stick in on reboot, I find that the host OS will not start

Given that I need to repair (which is something I know nothing about) or reinstall the host OS (linux Mint) is there a way to get all of the VM's and their associated files moved to a spare drive in order that I can put them back after the new install?

I have a little experience of command line if that is the preferred way

So, asking for guidance/links that will save a lot of work

Thanks guys

[socratis]

New user attempting to get files on host to be movable to vm and in the process, probably having left a stick in on reboot, I find that the host OS will not start

I'm not sure I understand this part, can you elaborate?

is there a way to get all of the VM's and their associated files moved to a spare drive in order that I can put them back after the new install?

See the FAQ: Moving a VM.

[OldChap]

Files on host are said to be able to be copied into folders on the VM.
I had Vbox extensions loaded OK but my reading suggested that I needed Guest additions too
I seemingly installed that even though there is no mention of it on downloads page that I saw, then rebooted the host
It was not until It would not get all the way into the OS (began cycling at the point where the desktop opens) that I realised that the stick that I was attempting to use to move files was still in the machine
Since then it will not start fully.

Thanks for the link

[socratis]

I'm sorry, but I still can't make heads or tails from your description.
Let's hope that the FAQ turns out to be useful for your case...

[mpack]

Files on host are said to be able to be copied into folders on the VM.

Yes, the feature is called "shared folders". Though one correction: shared folders make designated host folders visible to the guest, not the other way around. For security reasons it's good practice to designate a simple folder and keep nothing in that folder that you wouldn't want published on the internet: no sharing of the entire host C drive. Also do not store any executable files in there if you'll ever want to execute them on the host.

I had Vbox extensions loaded OK but my reading suggested that I needed Guest additions too

Not "too". Shared folders are a feature of the Guest Additions running in the guest and communicating with the VirtualBox software on the host. The host extension pack is not involved in this feature.

I seemingly installed that even though there is no mention of it on downloads page that I saw

Naturally there is no mention of the GAs on the downloads page, as it is a built in feature of VirtualBox, not a separate download.
If it required a separate download then you can be sure that the manual would say so. As it is, do make sure that you have carefully followed the instructions in chapter 4 to ensure that the Guest Addition drivers have been installed in the guest OS.

[mpack]

However, reviewing the first post, your problem seems to be that you want to back up a VM, which you certainly wouldn't do by copying files out of the VM onto a host drive - so all of that seems to be a red herring. VMs are just host files, so you would simply copy those host files to a backup drive as described in the FAQ which Socratis referenced.