Help with COD4 and punk buster

I have been playing COD4 for a while now, but when ever i try to play online I get kicked straight from the server by punkbuster. It tells me that I have a permanent ban on my user name and gives me a ban code wich is for aimbot or something. I do not have aimbot on my computer and ave never used it. everytime i change my user name it just gets banned like the rest of them. Please can someone tell me why I cant play on punkbuster servers.

your CD-Key has been used to use cheats by the looks of it, try contacting the Punkbuster or CoD4 people and explain to them. and try updating your PB.

Re-installing and updating PB will most likely fix the problem.

Once you have it working again, you should join the Call of Duty 4 [CF]Clan www.cfclan.co.uk

Change your IP address.

Mate, i had the same problem with PB on WarRock!

Every account i used got banned for no reason and when i tried to talk to them they just closed the topic i started within 24 hours or just reply with an automated message.

And everyone though PunkBuster was going to do good! lol