Recover Keys is a shareware product, there is no evaluation period for demo version. Some features are disabled.

Recover Keys Features
Recover Keys retrieves activation keys for 959 installed software packages, including such popular products as Microsoft Windows and Adobe Photoshop. You don't need to pay for your lost keys again - we are here to save your money.
Recover Keys allows you to find all the software keys on all your network computers.
As additional feature retrieve registration info, such as Username, Company, Product Id, Auth. Key.
Handy to backup your registration data. Allows to exporting data into HTML, TXT, RTF, Word, Excel, CSV and XML formats.
You can change a program activation key directly in the Recover Keys window without having to reinstall the program.
If you have more than one Windows operating system on your PC, Recover Keys can scan all of them.
Ability to filter keys scanner by software title.
Ability to filter keys by registry node (HKLM, HKCU, etc).