Can someone tell me where to get the registration key for Opposing Force from the registry? Due to a losing battle with a virus (and an excellent excuse to upgrade my machine) I'm wiping my hard drive completely and starting over. Before I do so I've been getting all of my keys from the registry and have gotten my Valve HL key but can't seem to find the one for Gearbox. Can anyone direct me?

Please note that I am not asking for the key, it's in there somewhere I just need to know where. Also I know you can generate keys at ************* but I'm not interested. My attempts at Sierra tech support usually get me nice generic responses which get me nowhere. Thanks for your help.