Office Key off Old Hard Drive

Is there any way to find my Office 2007 product key off my old hard drives? My motherboard crashed and I had to get a new PC but my two hard drives from the old system still contain all the program files I had. I’ve got a trial version installed now, but need that product key. I’ve tried contacting Microsoft but I apparently don’t know the secret handshake to get to the right person. Anyone out there, who can hear me?? HELP!!