If you purchased and installed the program, but have not been asked to enter the serial number, to unlock the full features you should activate ABBYY FineReader PDF 15.
In order to activate ABBYY FineReader PDF 15:
- Run ABBYY FineReader PDF 15;
- Go to Help> About> License Info;
- Click on Activate;
- Enter the serial number of your copy of the program;
- Proceed with the Activation Wizard.
Related article: How to activate ABBYY program?