WARNING: please use those for legit purposes. Do not try to steal product keys from this way.
Let’s say for whatever reason you need to find out your Windows 7 Product Key or Other MS Software key that you’ve already installed. Most likely reinstall Windows, or other software that you’ve already purchased. We’ve got you some tools that can help you to do this.
A List of Key Finders that works on Windows 7
Finds Keys for Operating Systems: Microsoft Windows 7, Windows Vista, Windows Server 2008, Windows Server 2003, Windows XP, Windows 2000, Windows ME, Windows 98, and Windows 95.
Finds Keys for Other Software: Microsoft Office 2007, Office 2003, Office XP, and several non-Microsoft programs.
Finds Keys for Operating Systems: Microsoft Windows 7, Windows Vista, Windows XP, Windows 2000, Windows ME, and Windows 98.
Finds Keys for Other Software: Microsoft Office 2007, Office 2003, Office XP and Office 2000 SP2, and Office 97.
Finds Keys for Operating Systems: Microsoft Windows 7, Windows Vista, Windows XP, and Windows 2000.
Finds Keys for Other Software: Microsoft Office 2007, Office 2003, Exchange Server, and SQL Server.
Finds Keys for Operating Systems: Microsoft Windows 7, Windows Vista, Windows XP, Windows Server 2003, Windows 2000, and Windows XP.
Finds Keys for Other Software: Microsoft Office 2007, Office 2003, most Adobe products, and many more.
Finds Keys for Operating Systems: Microsoft Windows 7, Windows Vista, and Windows XP.
Finds Keys for Other Software: Microsoft Office 2007, Office 2003, and Office XP.
Finds Keys for Operating Systems: Microsoft Windows 7, Windows Vista, Windows XP, and Windows 2000.
Finds Keys for Other Software: Microsoft Office 2007, Office 2003, Exchange Server, and SQL Server.
Product Key Finder (OTT Solutions)
Finds Keys for Operating Systems: Microsoft Windows 7, Windows Vista, Windows Server 2008 & 2003, Windows XP, and Windows 2000.
Finds Keys for Other Software: Most Microsoft Office and other Microsoft programs, and many non-Microsoft applications.
Finds Keys for Operating Systems: Microsoft Windows 7, Windows Vista, Windows XP, Windows 2000, Windows ME, Windows 95/98, and Windows Server 2008 & 2003. 64-bit versions are also supported.
Finds Keys for Other Software: Most Microsoft Office versions including Office 2007, plus a long list of other Microsoft and non-Microsoft programs.
Finds Keys for Operating Systems: Microsoft Windows 7, Windows Vista, Windows XP, Windows 2000, Windows ME, and Windows 98.
Finds Keys for Other Software: Microsoft Office 2007, Office 2003, and Office XP.
[Source via about.com]