Windows To Go comes to mind.
It allows you to use an existing computer that runs windows 7 or higher, but use external storage to store your settings, so you combine both to work with your desktop. You can then move the harddrive to another windows 7, 8 or 10 computer and work on that machine too with your settings.
The internal drives on that computer won't be available though.
Windows To Go is part of Windows 8 Enterprise or Windows 10 Professional and above and can be found by going to the Control Panel (not to be mistaken with the settings app), and showing all icons.