When using Windows 10, you may find that after a fresh boot of the computer, the order of the Game Controllers has suddenly changed.
You will find that your controls are not assigned the way they used to be...
The cause of this appears to be the 'fast start' option, it is new in Windows 10.
And, by default, after installing Windows 10 it is switched on.
So, switch it off!
How?
Simplest of ways is by disabling 'Hibernation', as most of us are using desktops and have no need/use for hibernation.
Switching it off, also gains you some space on the system disk, side of some 75% of your computers RAM memory.
Right click the Windows icon bottom left in the taskbar.
Select 'Command Prompt (Admin)' from the menu.
In the dosbox that now appears, type the following command:
powercfg /h off
(It will return no messages, if it does, you've made a typo, or have not started the command prompt as an administrator.)
Next, type the command:
exit
All done!