As per the Higher Editions section of our Policy page, you can move up to a higher edition of our products by simply paying the difference in price between what you paid for the lower edition of the product, and the current retail price of the higher edition that you wish to move up to. So in your particular case, you can move from the 15-user “Business Edition” of WSE RemoteApp 2016 up to the 25-user “Professional Edition” for only $75 USD (i.e. the current difference in price between the two editions).

If that is agreeable with you, then contact us for a direct PayPal payment link that you can use to submit your $75 USD payment. Once your payment has been received, you will be sent an email message containing your personalized registration information (with the exact same User Name, but a brand new Registration Code) for use with WSE RemoteApp 2016 (Professional Edition). You can then use that new registration information to re-register the product, and it will automatically be moved up to the higher edition. There is no need for you to uninstall/reinstall the add-in, and all of your published RemoteApp programs, settings, etc. will remain intact during the registration process.