My key won't work in the multiplayer mode it works fine in the single player but in multiplayer it tells me my code is in use. Someone please help me.
I used CD KEYs DIRECT once, but there are others you can buy an online key from. There is an issue with COD4 not disconnecting your CD Key properly regardless of whether your game crashed etc. Simply logging out normally from the game will cause the 'CD Key In Use' error. I have two computers with COD4. One has original sealed retail install with its original key and the other PC has an installation from the retail CD, but with the key I purchased online. Both have Keys worked at the same time as well as individually, but both get the same error frequently. Rebooting your modem will cause the master server to drop your CD Key from use 90% of the time from others and my own experience.
It is NOT an issue of your 'CD Key In Use', a duplicate key or otherwise (unless your friend borrowed your game maybe.) It IS an issue with the master servers registering your key as still logged in. Thus far the issue has not been rectified and appears to be quite random amongst the Battlefield and COD4 community and who knows who else...
Game support these days is lacking and now it's all about massive shipments and uploads for sales even though games clearly were not ready for retail market with some having more than a fair amount of bugs in them. A games shelf life and it's continued issues would not be something support wishes to dedicate too much time once sales decrease and the money made, so consumers have to lump it. This issue here is getting old.