rsAccessDenied on new reporting services report server link created by the reporting services configuration manager

rsAccessDenied on new reporting services report server link created by the
reporting services configuration manager

On a Windows 7 computer we installed SQL Server 2012 Business with the
reporting services.
We tried to use the reporting services configuration manager and chose the
default settings for the report server.
We now have a clickable URL link to the report server. When I click on the
link that was created, this error message is displayed:
Reporting Services Error
The permissions granted to user '<our computer name>\<our admin user>' are
insufficient for performing this operation. (rsAccessDenied) Get Online
Help
SQL Server Reporting Services
Can you tell us how to grant the needed permissions?
Thanks.