GTA 4 Activation not possible...

[TippeX]

or, alternatively check the gta iv forums / unlock / offline activation site, the game is 'past' release control, i think the gtaiv.exe that it downloads is available on the site..

so all you'd have to do is get that exe, replace the existing one with that, you've already registered so you don't need to go through that... should be all fine then...

link location for the exe is -> https://support.securom.com/rockstar...eInstaller.zip