virtualbox.org

A couple of times this month, I have received a 0xc000021a error during the startup of Windows 10. This always results in me having to retrieve what files I can using 7-Zip and performing a clean reinstallation of the VM - not convenient, I'm sure you might agree!

Sometimes I temporarily move the VM image to an NVME drive in a USB enclosure, in order to make space for other things. I do this by going to the user profile folder where I can see the "VirtualBox VMs" folder, which I enter and move the files from. Although I am quite careful anyway, since the error, I have always ensured the drive has definitely finished writing before using the "Safely remove" icon to eject the drive and remove it when I am told it is safe to do so. This drive has never corrupted any files, so I see no reason to suspect it - but I thought I would mention the fact I move the image to another drive in case it mattered.

I'd really appreciate any advice towards this, more to stop it happening again in the future.

I would stop looking to VirtualBox to explain this error. Treat it as if it happened on a physical machine. It seems to be a driver problem, and since all of the virtual hardware is well tested by many users, I would consider any third party drivers, e.g. for USB devices, that you may be using in your VM.

https://answers.microsoft.com/en-us/win ... d276db8514