I had the need today to find the product key for the office install from my wife's dead laptop. (The key is in storage in another state right now). A quick Google search found Magic Jelly Bean KeyFinder. The program worked great. I just hooked my wife's drive up to my own computer as an external hard drive and then launched KeyFinder. Under the program's Tools menu I choose "Load Hive" and navigated to the "Windows" folder on the external drive. The program found the keys for her operating system install as well as installed office programs and even a few others.