Once you've entered the license key, the following file is created on the Windows file system,
and the file will contain the License Key along with other license metadata.
normally this will be located at C:\ProgramData (C:\ProgramData\PowerWorship\pW4\License\Pw.License)
depending on your Windows installation, but if you can't find it there, you can enter the path to
%programdata%\PowerWorship\pW4\License in the Windows File Explorer with the %programdata% environment
variable in tact, and it should resolve correctly.
The text portion of the file (including the license number) should be visible in Notepad or Wordpad,
but be sure not to edit and save the file, if you do open it in Notepad or another text editor.
That said, the existence of the file is enough to tell you whether you entered the license number previously.