Macbook Air ignores our strong cable signal and tries to connect to other sources We have a Virgin Media cable provider and most of our neighbours are Sky or BT.  All available networks appear in the drop-down on the top menu and indicate if they are secure or not.  Ours is the strongest signal, yet repeatedly it is pushed to the bottom of this list and my Mac tries to join a BT one.

I want to just remove all these BT and Sky Wi-Fis so the Mac always defaults to our provider and never tries to connect to them, but solutions supplied elsewhere don't apply.

When I go to the Advanced menu on the WiFi preferences, these BT and Sky options aren't there.  How do I get them off the dropdown menu or just tell Mac to ignore them permanently?
Have you tried System Prefs &gt; Network &gt; WiFi
Switch off 'Ask to join new networks', then in the Advanced... section below, you can drag networks into your preferred order &amp; delete ones you no longer wish the machine to remember [this will tie in with 'Ask to join...' &amp; shouldn't bother you again].