Avast Licence Expired in Limited Account

I was able to enter the licence key for avast FREE home in the administrator mode
and avast works fine.
However when I created a second limited account, avast is able to start
and prompted me to enter my licence key.
I tried to enter it, but it says that licence key can only be enter in admin account.
I switched back to admin account to renter the licence key
When i switch back to the limited account, avast prompted me to enter the key and is unable to load.
What should I do?
Help is appreciated.
Thanks a lot.

Try adding the key and boot the computer.
Then try to log the non-administrator account.

Do you have more than one account with admin rights?
avast (and other products) doesn’t work well with this situation :-[