We created a fix for the game not starting up on Windows XP 64 and Windows Server 2003 systems. This patch has not undergone the same amount of QA as the released demo so I strongly encourage to ONLY replace the UT3Demo.exe with the one from the patch if you are experiencing the "Modified executable code is not allowed" issue at startup.
Demo installation went off without a hitch, and within minutes we were in-game and at the login screen. Unlike previous versions of Unreal Tournament, UT3 now requires you to create an account and log in to play. These accounts are tied into the GameSpy ID system, so if you already have a GameSpy ID associated with your email address then you’ll need to enter your GameSpy ID password to create your UT3 account. This gives an extra layer of security against cheaters and other 'tards that wasn't present in UT2004, and while in the beta demo you could just enter a load of garbage in the email field without consequence we presume that the full version will tie your account to your CD-key in some way.