Recover login password, without resetting it.

Ok, I know how to reset and bypass a Windows 7 password, but I need to recover it if possible.

Let me explain why; I'm working on a laptop that is not mine. It belonged to a young man who passed away suddenly about a month ago. The family would like me to recover as much data from this laptop as I can for sentimental value, because they want it reformatted so that the family can use it. However, the system has a password. In case this password might have been used for other things, I'd like to know what it is rather then bypass it. (There is a hint XKCD which I'm aware is a webcomic but no idea what the password could have been based on that alone).

Anyway, having the password would be nice rather than bypassing it. Any ideas on how I could pull this information from the system?

Worst case senario I'll just reset it, but I was hoping someone might have some idea of how I can recover it.

Thanks!