Not sure if relevant, but here a registry snip concerning UAC / Metro apps and the built-in admin account.

http://forums.mydigitallife.info/threads/46105-Windows-8-1-Registry-Tweaks

Windows Registry Editor Version 5.00   ; Enable Metro Apps to Work on In-Built Administrator Account with UAC Prompt Disabled (Requires Reboot) [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System] "EnableLUA"=dword:00000001 "FilterAdministratorToken"=dword:00000001 "ConsentPromptBehaviorAdmin"=dword:00000000 "ConsentPromptBehaviorUser"=dword:00000000 "PromptOnSecureDesktop"=dword:00000000   

Edited November 22, 201312 yr by MrJinje

Unfortunately, UAC prompt disabled and UAC truly disabled are not one and the same.

That tweak has EnableLUA = 1, which ENABLES UAC and defeats the entire purpose of being a full-time Administrator, where your computer just does what you tell it to.

However, I'll have to experiment with those settings to see if maybe there's some kind of side effect behavior that allows the Metro/Modern apps to run even when EnableLUA = 0.

UAC has a purpose: To protect unwitting computer end users from themselves. The trouble with self-protection is that it gets in the way of people who know what they're doing and don't need to be nagged by failures to access things they have every reason to access.

-Noel