I forgot password of my minirouterboard 150 and I found that only way is to reinstall it. I am afraid to loose licence. How long can I upgrade my routerboard? When the coundown starts?
Also I Downloded file routeros-rb500-2.9.42.npk, on page that say "Use these files if you have a RouterBOARD brand system (RB100 or RB500 series)."
But my board is rb150, so I am confused because name of filename contains only rb500. Software on routerboard is 2.9.35.

RB150 is RB100 series board, it means that you must use package for routerboard.
As far as i know there are no time limits for upgrading anymore.