Everytime i try to join a game in multiplayer, i keep getting an error message saying "Cd Key being used. Try reconnecting later", or something similar to that. Any idea why this is happenening? I cant even connect to an empty server, and i have patch 1.4. plz help
Is the game bought from a retailer?
You won't be able to play with an invalid serial number, or somenody must've stolen yours.
Yes, its a retail, but is there any way i can play on MP now?
I think what Fezarella really meant is "did you buy the game DIRECTLY FROM THE STORE and have you made SURE that no one else borrowed or even TOUCHED your CD case where the CD key is printed?" Make sense why we ask that? ;-)
Anyway, there have been cases where CD keys were stolen. Hackers have "cd key stealing" applications (one was posted on my moderated www.codboards.com recently!) and when people download them and install them, instead of getting a neat CoD utility they get spyware that sends their cd key to the hacker's site.
Another way is if you have file and print sharing turned on and you don't have a firewall on your computer. Hackers can use tools to get into your machine and get the cd key that way.
I'm assuming here that your cd key has been compromised of course.....
But, see this from Activision support too:
CD Key in use Question I receive a CD Key in use error. Answer Be sure that your computer is not behind a software or hardware firewall of any kind. This includes firewalls built into routers or other equipment, as well as programs like Zone Alarm, Black Ice, and the integrated firewall in Windows XP. Activision does not support the use of our games from behind a firewall. If it is not possible to disable the firewall you will need to open the ports for Call of Duty. Call of Duty transmits and receives network traffic on port 28960 using both TCP and UDP. The exact details on opening a port is specific to your firewall. For more information check with the firewall documentation or manufacturer.
Another common cause of problems is a poorly configured router or connection sharing solution. If you are using a router, ICS, NAT or a software gateway you may have problems playing on the internet. This is because the router may not be forwarding the correct information back to your machine. It may be possible to get around this problem using port forwarding or DMZ. You can find more information on configuring shared connections for multiplayer gaming at www.practicallynetworked.com. Please be aware that like a firewall we cannot actively support using shared connections to play online.
The most common cause of problems though is usually the simplest - an overburdened network stack. By default many computers have protocols the average person doesn't use; things like VPN or NDISWAN. You may want to contact your ISP to find out exactly which protocols you can safely remove. Often times network game problems are resolved by something as simple as removing unused adapters and protocols.
The problem may also be related the the status of your ISP or that of the server. Due to the dynamic nature of the internet and the variable levels of traffic, it is impossible to completely eliminate this error. If you are having persistent problems you may wish to try a different server, or just wait and play a little while later.