While downloading the PrestoExpert Messenger it's common for experts with a personal firewall to receive a message from their anti-virus software identifying the program as "unrecognized".

For the program to function properly, it must be able to connect to the internet. If you receive a message stating that the program is unrecognized and asking if you'd like to allow outbound access to the internet, click "Yes".

This should resolve the problem and allow the PrestoExperts Messenger the access required to install and function properly!