Parallels Problems Across Multiple Users

My wife has just bought our first MAC and she needs to run certain things under PC Office for her business so I have installed Parallels. The problem I'm having is that when I login for my daughter to use the machine I constantly get the following:

You don't have permission to use the application "prl_natpd."

I then get 3 options

Always Allow, Allow Once or OK.

No mater which I press and what admin password I use this box comes up every few
seconds and makes the login un usable as it's right in the middle of the screen.

I don't care if parallel is or isn't available to my daughter, she won't use it.

Can someone tell me how to get rid of this.

I'm a long time PC user and have used iPADs, but I'm new to the MAC and certainly haven't learnt to love it yet!