The menus are in CRM itself as Tabs.
Administration -> Customization -> Users
and click on the "Tabs" tab.
Here you will see 2 or more menus
PortalLogonMenu - This is the menu that the user sees when they are not logged in
PortalSupport - This is the menu that users see when they are logged on to the portal
Portaldownloads- Used to configure and control downloads from the downloads.aspx page