Windows 10 won't boot unless the installation disk is inserted

Nisko said:

Did it again after opening command prompt. This is the result I got: Could not map drive partitions to the associated volume device objects:
Access is denied.

You have to use Administrator command prompt

Get a copy of Lazesoft recovery.
It does all quite well for you.
You need to create on another system a bootable CD first and then boot it on the "patient".