Recently, we got a laptop that did not have a right Ctrl button and we found out after we started a VM with no Guest Additions installed.
Because of these two factors we could not escape the VM capture mode and return to the host OS.
To resolve the issue, we pressed Alt+Ctrl+Del to force the window to escape by entering that specialised Windows security screen and the hit Cancel.
Then, we went to the VirtualBox window and did the following procedure to change the button that allows you to escape the capture mode.
From the VirtualBox Window menu we went to: File –> Preferences –> Input and then clicked on the box next to HOST KEY COMBINATION and then typed the key we wanted to use.
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