I have downloaded Grand Theft Auto 4 for PC. Notably, I have the actual two CD's. But, when I try to play I can;t. I don't know how.

It is asks for a SERIAL. What is my serial?
when i put in the serial number that the first answerer gave me it said.... Activation process has been terminated

For additional information, please visit our support homepage: http://activate.rockstargames.com/?c=GTA4
Internal error message: unlock code was revoked