There could be several scenarios when somehow you have lost the key for one of your already installed application. This small application Magical Jelly Bean Keyfinder, retrieves the Product Keys for applications installed on your System.

You need to download it, as a 330 Kb zip file, unzip it, and run the keyfinder.exe, it will show you the Product keys for your Windows OS, and several other installed applications, which can be printed, or saved in text or CSV format.

Product Key Finder

You can also retrieve the Product Keys from the registry of other Windows installation, which is not active at the moment, this can be done using the Load Hive option, you need to browse and point the Partition from the Slave HDD, or from other partition on Primary HDD.

Product Key finder options

Config file can be edited to retrieve the Product keys for the applications which are not mentioned in the Config file by default, like I have Camtasia 5.0 installed on my system, and the default Config file which came with the application, has Camtasia 4.0, so I edited it to 5.0 from 4.0, to get the Product Key for Camtasia 5.0.

So now feel free to lose the Product Keys, just by downloading a 330 Kb file, lol, well jokes apart this definitely is an awesome rescue resource, save all the Product keys in one file (txt or CSV). Find more by  Downloading Keyfinder