After buying the app a customer receives a registration e-mail with the registration code. After that go to menu Help->Enter Key:

or from the reminder dialog:

Enter the registration name and code from the registration e-mail:

Registration data should be saved to the text file 'license.dat' which should be placed into the program folder. File contents:
The first line - registration name
The second line - registration code
Example:
John Smith
KGT4-YGRT-GHTR-7G31
This topic is a part of Uninstall Tool support articles. See more pages:
Don't hesitate to contact CrystalIDEA if you have any questions.
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