ARAS, when first started, utilizes the default http port number 80. This http port number is also used by default by other Internet programs like IIS etc.
What is occurring is that a service, whether IIS or another, is presently running and utilizing the http port 80, and ARAS can not initially start so you can configure it to use another port number.
In theARAS Installation & Configuration Guide, it is recommended to check your Services (Programs -> Administrative Tools -> Services) and shut down all Internet related programs before first running ARAS.
You can than start ARAS and configure it and the http port to another number as needed.
Than restart your IIS or other program that was using the default http port