There are situations when you need to retrieve / recover your windows 7 product key, losing your CD / Box is one of the major ones. First, always backup your keys, in-case you need to reinstall. That’s when these free applications come in handy.
WinGuggle is a portable (free) application that lets you reveal your existing OS’s CD key in seconds. Just run the app and it will show you the key which you can copy by clicking “Copy”. Another option you’ll confront is “Tools” where you can see the Manufacturer, Model, Website etc of the system. A handy tool for recovering windows 7 product key.
LicenseCrawler is another utility that lets you reveal (almost) all the keys for the installed products. Again, it’s a portable application, after running, you’ll see some options; You can select multiple computers (If have access, through LAN), select HKey_ALL and start search. It will display all the CDkeys of the applications installed.