Before the Windows 8.1 update, I was able to map Caps-Lock to Controls through the type of registry tweak in this post:
However, after updating to 8.1, my tweak no longer works. What I had done was
Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Keyboard Layout] "Scancode Map"=hex:00,00,00,00,00,00,00,00,02,00,00,00,1d,00,3a,00,00,00,00,00
Windows 8.1 may have changed how it interprets the keyboard layout registry, I'm guessing.
I'm an avid
emacs user, so this problem is a life-or-death scenario for me.