A Virtual Machine virtualizes everything in it, including system files for that VM. You are basically running another copy of the OS under your main OS. The advantage is that you can make a copy of a VM once you have it set up, and then if anything happens to it you can delete it and recreate it from the saved copy. The disadvantage is the setup process.

More links to check out:

https://www.makeuseof.com/tag/create...drive-windows/

https://smallbusiness.chron.com/move...ter-68942.html

https://smallbusiness.chron.com/copy...007-47497.html

https://windowsreport.com/windows-7-migrate-virtualbox/

https://www.sevenforums.com/virtuali...p-machine.html