Lost SQL Server 2005 product key. How to find installed SQL Server product key?

If you have SQL Server 2005 installed on your computer, you could find lost product key with effective software, iSunshare Product Key Finder.
How to Find Product Key with iSunshare Product Key Finder

Step 1: Install Product Key Finder on your computer.
The computer is which one where SQL Server 2005 installed.

Step 2: Click "Start Recovery" button.
Few seconds later, SQL Server, Windows, Office, IE etc product keys are listed in Product Key Finder.

Step 3: Click "Save" button on menu or "Save to File" button to save product keys for them.

This way to find SQL Server product key also applies to SQL Server 2000/2008/2012/2014.