Shareware License
You are welcome to evaluate the program for a certain period of time mentioned in the program without paying. If you would like to continue to use the program after this evaluation period, you have to purchase a license key. Extended usage requires the product to be licensed. We encourage you to license the Software and support its further development. To license the program, please go to the Viper FTP website to purchase a license key at:

Viper FTP License Key
By registering and completing the payment process you obtain a license key for the Software.
Upon receipt of payment, the user is granted a non-exclusive license to use Viper FTP on as many computers as defined by the licensing terms according to the number of licenses purchased, for any legal purpose.
Distribution of the licensed version is not allowed. You are not allowed to distribute any kind of registration codes, license keys or algorithm to build them.
You may make copies of the Software only for backup and archival purposes.

Enter your License Key
To register your Viper FTP copy, enter the license key you received. The registration window is displayed everytime you launch unregistered version of Viper FTP. Press "Enter Serial Number" button to register your license:
Viper FTP Licensing
Viper FTP icon

Viper FTP User Guide

You Then copy your licesnse from the email to the text filed and press "OK" button: