Xfinity window at Startup

Its not the Xfinity toolbar in my browser that needs to be removed.......Its a seperate *window* which keeps appearing after startup regarding signing up with Xfinity when i already have been a member and its unecessary.....Im just looking to find a way to remove the window i see each time i start my computer.....I will submitt a screenshot to indicate what it is i see........

If anyone ever gets this, the solution is to turn off *WIFI* in Network Prefs.....

As far as Network Preferances is concerned, *Ask to Join New Networks* is disabled, and nothing else appears in *advanced Preferrred Networks* other than xfinitywifi because this is the carrier i use to establish connection with.....So everything is ok with what i follow you on, yet the window still appears as shown...

It requets your login and password , but im already an Xfinity customer, all of this signing up is unecessary, all i want to do is remove the window, this has happened before in the past but i have forgotten how someone had indicated to me to have it removed, it was years ago

Yes, i will ask them,...thank you for your input none the less....much obliged....