default lockscreen, can't change it

So, this is my first thread, so sorry for anything I do wrong here...
Also english is not my native language, sorry about that too
Anyways, I tried changing my lock screen and it shows the default, but I can't change it
View attachment 50006
I've been searching for hours now and can't fix it...
Thanks in advance

https://www.google.com/?gws_rd=ssl#q=windows+8.1+keyboard+shortcuts

The default for locking the keyboard is the Windows key plus L [for those who haven't tried it]. Using it will require the login password to get back into Windows. Frequently shortcuts for the keyboard can't be changed but maybe one of the pages found on the above link will have a how-to for remapping. Biggest problem I see is in choosing a combination that is not already in use by Windows or by various programs which could cause other issues.

Is your Windows activated? You can't change the lock screen if not. Have a look on PC Info as below.

If it is try http://www.eightforums.com/tutorial...ault-background-image-change-windows-8-a.html