How to protect against disappearing VMs

[francob]

I recently lost a VirtualBox 4.3.20 Linux VM that took me months to build - the \.VirtualBox and \VirtualBox VMs folders just suddenly disappeared. Fortunately I had a fairly fresh backup of the host (a Win 8.1 machine).
1. What could have caused this (I suspect something like Ccleaner)?
2. More importantly, is there any way to protect these folders so nothing can remove them?
Thanks.

[noteirak]

1. What could have caused this (I suspect something like Ccleaner)?

VirtualBox does not perform any deletion of that kind, so some third party software is. There is no way to know from a VirtualBox point of view.

2. More importantly, is there any way to protect these folders so nothing can remove them?

Well... Nothing in VirtualBox can these are just regular files, which can be access by the user owning them and the system. If any other process is running under these credentials, they are free to do what they please!

Bottom line: you should really double check what software installed on your machine is doing... Nothing we can do here I am afraid.

[loukingjr]

FWIW, CCleaner would not normally delete those folders unless it was used to uninstall VirtualBox. CCleaner is fairly good at finding ALL files associated with a program.

[mpack]

VirtualBox does allow you to delete VMs, but it has no function to delete the ".VirtualBox" and "VirtualBox VMs" folders.

Are you sure you didn't just log in as a different user? Have you been doing any fiddling with user accounts on that PC? Come to think of it, I have no idea what happens to user doc folders if you delete a user profile on Windows. I assume they remain behind, but accessible only if you have admin rights.