When you purchase the program you receive your private license key. Click the Enter Key button in the reminder window that appears when you start the trial version of the program and enter the key (use the clipboard to copy the key to this window). Click OK and restart the program. Once the key is entered you will be able to use Absolute RSS Editor without any limitation and will no longer see the reminder window.
If you would like to purchase Absolute RSS Editor visit https://www.alentum.com/purchase.htm.