Legend0fGame

I just downloaded the Arma2 CO package off of Steam today in order to participate in DayZ. I downloaded the Six Launcher and updater just like I was told to on the download page on this website. I have done everything exactly as it was written and when I try to launch the DayZ mod, I get an error that says, "Bad serial number given in Setup." This is very aggravating and I would like to have the issue solved if anyone knows the solution.