Yeah, I'm getting much the same problem. I originally had the Digital River download, everything ran just swimmingly (all things considered) but recently I got back into the game and I couldn't play any new missions online. So I uninstalled my game completely, installed it fresh, and am now getting the "Bad serial number given during setup." I don't recall doing anything differently from before. I'm a noob with registries so I don't care to get in there and tinker, but I've uninstalled and will try a fresh installation and patch. It would like to know how to manually enter the key (I've got it right here in my e-mail from Atari) using the system registry. I probably have a problem just like Pokletu's, since I have both a C partition and a D partition on the same physical hard drive, C containing Windows and D containing games. The temp goes to C and the game goes to D... anyway I'll try a reinstall, but do answer for us soon. Thanks.