Help with Lock Screen and WStore! Windows 8.1!!

[Marcador]

Hey guys, I'm having 2 issues since I updated my W8.1

*I'm Brazilian, so my OS is in Portuguese, I think you can understand what's happening in the screen

1. Can't change my Lock Screen

Since I've uploaded I can't change, and it's the same as the one I used in W8, it's a customized one(Darth Vader) and I can't change.

Notes: I've checked in the folder of the customized Lock Screens as it's in some tutorial in the forum and it shows the one I can't change as "Lockscreen_A" and the one I'm trying to change it to as "Lockscreen_B", but it seems to be having no result as the "A" is still working. I've clicked in the default ones to change to them, but again, no result.

I have 2 users for this notebook, and for the second one it's totally normal, I can change it perfectly, and the second is just an "User" acc and I'm ADM.

2. Windows Store not finishing the "loading"

I think this is the tricky one... It was working fine when I uploaded for 8.1, but since yesterday it's not working at all, and I'm not receiving any error messages, I think it started after the updates for 8.1(not the update TO 8.1, but FOR 8.1).

The app just loads and after some seconds it goes to the left area, where the apps go when they are minimized. And goes to the desktop, I click on the app again it does just the same thing.

Notes: In C:\Windows\Temp I've found this file:

Soon I'm gonna try in the other user.

PLEASE, help this man!! :)

[Marcador]

*Forgot to mention that other apps are working fine.

*The Store still works in the other user.

*I was able to open Store by the option to "Rate and to Give Opinion" in the Facebook app. But when I go to the Homepage of the Store the same problem happens...