When installing SQL Server 2019 Reporting Service or 2017 and later, you will be ask to enter product key.
Actually there is another way to get it.
When we run setup.exe from the media, the Product Key is picked from DefaultSetup.ini file located under RootX86 or Rootx64 folder. This file is also used to make slipstream media (refer KB)
The file would look like below
Comment if you know other way to do this too.
This post first appeared on Ben's System Center Experience. Read the original article.