The serial number used to activate "Grand Theft Auto IV" is located in different places, depending on how you purchased the game. Finding a serial number is required when installing or reinstalling a game to a game console. If you installed the game via Steam, check the Library tab for the serial number, and if you purchased a hard copy, then it should be in the manual that came with the CD.
- Find the serial number in Steam
Load up Steam if it isn't running. Select the Library tab. Right-click on the game, and select "View Game CD Key." A pop-up displays the serial number.
- Retrieve the serial number from the manual
Find the original manual to the game. Look on the back cover to locate the serial number.
- Recover a lost serial number
If an activated version of "Grand Theft Auto IV" is installed on your computer, you can recover the serial number by using product key-finding software. Use a program such as Magical Jelly Bean Keyfinder or Winkeyfinder to recover this information.