How can I deploy ADNM and the managed clients on a network with another (non-avast) anti-virus already in place?

Q: How can I deploy ADNM and the managed clients on a network with another (non-avast) anti-virus already in place?

You should first remove (uninstall) the current antivirus program before starting the installation of ADNM and the avast! managed clients. This will prevent any conflicts or problems in the future.