GTA IV originally used Games for Windows Live (GFWL) and SecuRom , both of which are largely defunct or have been phased out. Most "keys" found in old text files will no longer work with the modern version of the game. The "Complete Edition" Solution
G4T4-KEYX-N0W4-Y5T1-LLH3R3
, Rockstar Games replaced the original version of GTA IV and its expansions with Grand Theft Auto IV: Complete Edition Removal of DRM : This version removed dependencies on Games for Windows Live (GFWL) and the legacy SecuROM activation system. Redemption Grand Theft Auto Iv License Key.txt
If the launcher asks for a key, paste the one from Steam. It will look like: XXXXX-XXXXX-XXXXX-XXXXX-XXXXX . This works forever. Dynamic Examination: Grand Theft Auto IV License Key
However, many of those old license key text files are for the 2008 version. If you find a key and try to use it on Steam or the Rockstar Launcher today, you will get the dreaded "Invalid Product Key" error. You cannot mix original CD keys with the Complete Edition. Redemption Step 4: Manual Activation (If Required) If