Problems with users trying to register

Hi I have started a forum
every single person including other admin who have tried to register
gets the answer this user name has been taken. as there are only 7 of us
at the moment that is impossible. i have tried to register with another name and email address and it says the same thing to me. Until we get this sorted I cannot switch over to your forum for all our members as they will get very fed up trying to register and being told their name had been taken can you help

forum is lurchersos.forumotion.co.uk

Hi this is a very common problem with a usually easy solution.

Go into ACP --> Security --> See this option "Unauthorize subscriptions made with the most commonly used spam usernames" and Select No --> Save

Is this solved?

Yes it is solved thank you very much