Sometimes VirtualBox doesn't behave when it imports Virtual Machines (appliances).

I exported a Windows 10 VM from one machine to another, imported and ran it to receive a recovery message on launch.

My W10 VM isn't happy

The error

A dramatic message:

Your PC/Device needs to be repaired

This 64-bit application couldn't load because your PC doesn't have a 64-bit processor. If you're using Windows To Go, make sure that your USB device has a version of Windows that's compatible with the PC that you're trying to use.

File: \windows\system32\winload.exe
Error code: 0xc000035a

You'll need to use recovery tools. If you don't have any installation media (like a disc or USB device), contact your PC administrator or PC/Device manufacturer.

The solution

This happens frequently, but it's a simple fix. The config has just forgotten it's version:
- Machine > Settings > Basic
- Update the Version drop-down to the correct OS and version

Correct the OS version in the machine config

In my case it had reset it to Windows 7 (32-bit) when it should have been Windows 10 (64-bit).