Remove Libraries from Windows 8 Explorer sidebar
Solution 1:
Just found the solution in this other thread about Registry Permissions:
Launch the regedit
with WIN+R and go to the following location:
HKEY_CLASSES_ROOT\CLSID\{031E4825-7B94-4dc3-B131-E946B44C8DD5}\ShellFolder
Open the "Permission..." on the ShellFolder and open the "Advanced" settings
Change the Owner to "Administrators"
Now you can set "Full Control" to the Administrators and change the values.
Now double-click on Attributes
DWORD and change the value to b090010d
And then it is possible to change