The Vietcong 2 update patch fixes bugs found in the game since its release. In particular, it fixes the annoying, but random ‘CD key in use’ message when playing online. After downloading the file, unzip the its contents – there should be three files named ‘Patcher.exe’ ‘patcher.cbf’ and ‘patch.cbf’. All these files are present in the same directory. Be sure to unzip all the files first: don’t try to run Patcher.exe by itelf from within the zip file otherwise you will see a cryptic error message.