I'm pretty sure no one will be overjoyed to see this post here, but I don't know where else to turn. SimMarket directly says on their site that they don't offer any support. Only that I should go to my Purchase History to find my key, which doesn't help because I already know it. Yes, what they have and what I have is the same key. It also matches what's in my FSUIPC.KEY file. All that happened is that I got a newer PC, installed FS9, installed FSUIPC, and failed trying to register it. All I get is the message that it's not a valid 12 character key, or very similar words. I was surprised, because I've upgraded PCs before and never had any problem using that key. Granted, it's 8 years old, but I don't think that should matter. It's version 3.71, if that makes any difference. I'm assuming that an internet connection is not needed? If I'm in the wrong place, my apologies -- please direct me to the right place; I don't know where else that might be. Was hoping to see the problem covered in the FAQ, but no joy. Thanks for your indulgence. ...Dave Dave Jones Fort McCoy, Florida