How to explain to Windows 10 that it is the only one on the computer?

Question

Windows

Trying to make windows 10 on an external hard drive, the main Windows 10 began to complain about winload during boot, one of the points offering to start another OS, after a short boot it offers a choice of two Windows 10, the first one gives an error with winload and with the same sentence, the other the item loads the main Windows as if nothing had happened. CHKDSK did not help, neither did sfc, complaining that windows resource protection could not perform the requested operation.

Answer 1

This computer (RMB) -> Properties -> Additional system settings (in the left column) -> "Advanced" tab -> "Settings" button of the "Startup and Recovery" block -> settings of the "Load operating system" block.

Answer 2

use EasyRE (or EasyBCD itself)

Answer 3

Well, what's so difficult? https://codepen.io/aliencash/pen/mMpwKW?editors=1100

Answer 4

You can make a background consisting of several gradients:

background:
    radial-gradient(circle at center, #fff 50%, transparent 55%),
    linear-gradient(-45deg, #001510, #00bf8f);

code pen