Apple keyboard blues

Once again my Apple Keyboard was suddenly stopped operating with my MacMini.  After a few days of ignoring it (since I was busy on other stuffs), I found time to look into it, and eventually found out the reason: my iPad 1 was paired with the keyboard, and thus the MacMini faired to operate with it.  But then repairing the keyboard back to Windows 7 side of the MacMini took me some time and mostly trail and error.  Eventually it was working after I got internet connection (by tethering wth iPad 1).

Definitely a time wasting process for researching this.