Exclude max values for column

Exclude max values for column

Hi,
I want to find a list of who needs their software upgraded. 
So basically I want to find the 'installed version' and exclude everyone who has the latest version.

This seems to have the best clue, but I can't get it to work-

https://stackoverflow.com/questions/1182795/sql-query-to-select-everything-except-the-max-value