Cant check /uncheck users box for back up

I am trying to backup my user files. It is has not worked for 3 weeks. Window 8.1  I can not seem to uncheck the users box in the pic. lower left side. I can uner the users sub tree but not the whole users box. It always a  - sign stuck there. I am only guessing that this maybe why it is not backing up. Anyhelp would be great! Thanks

Hi, welcome to the community. 

The reason why you are unable to remove the “Users” folder for backup is because you have items selected within that folder, hence the reason why it have a dash instead of a check mark.

Are you the administrator of the computer? Do you receive any error messages from the smartware?