I have windows 8.1 i've made an new account on it now i have 2 accounts then the first one is signed in with this laptop and the new one isnt signed in and then i made the new one administrative and the old one is standard and when i want to do any changes to the pc it requires the password of the new account and when i enter it, it doesnt make the change it just disappear

Example when i want to change the old acc. To admin again it appear a window that i should enter the password of the new acc. When i enfer it it just disappear without openning the setting i want 

What should i do to remove the new acc. Or change the old acc. To admin again??