Are you referring to the setup file to install the Avamar Administrator GUI? If so, open a web browser, enter the IP address or DNS name of the Avamar server. then click the "Documents and Download" link at the bottom of the page. Scroll down to the Windows 32 bit section (even if you are running a 64 bit system) and click the first link. Then click the "AvamarConsoleMultipleWindows..." link to download the setup file.
An Avamar server has 2 authentication systems: The Linux OS, and the Avamar internal authentication. When you log on to the server through an SSh connection, you are using a Linux username/password. When using the Avamar Administrator GUI, you will need to log on using a Avamar Administrator internal credential. The default superuser administrator username is "MCUser". The password is usually set during installation to whatever the customer specifies, so I can't really say what your password is. Typically, you would not use the MCUser account often, except to set up a regular account name after the first installation.
There is a lot of info in the Avamar Administration Guide: Click here
All Avamar Documentation is on Powerlink:
I will also recommend the Avamar Administration course from EMC Education Services. It goes through all the basics, and more. http://edu.corp.emc.com