I have Inspiron One 2330 with Windows 8.1 (64-bit).  Reading various forums, we're supposed to get an icon on computer during one of the windows updates to be able to register for the windows 10 upgrade.  I have not received this.  Then I read that certain computers do not qualify and then others that may have certain features turned off and that's why you've not received the invite.

I have automatic windows updates, so how do I get this update invite for my personal computer?