You can begin using PDQ right away.  You can try PDQ 25 times. Use beyond the evaluation period requires registration.  None of the features of PDQ have been disabled.  However, you will find that aircraft must be re-entered after 10 loads.  After the 10th loading of an aircraft, it will be deleted and must be re-reentered.  Registration of PDQ will remove that restriction.

Registration costs just $49 and entitles you to all future upgrades free of charge.  You'll be notified as updates occur. Registration instructions are provided by Weight and Balance PDQ. 

Just click on REGISTER from the main menu.