any help

sorry to be asking this here, but can't seem to get any help elsewhere.  once a user log in they have a menu that shows my account, my mail, my profile, my presence and log out.  how do you change the links to these menu items.  all is well except the "my profile" link.  it points to http://mywebsite/test (where test is the test user i've created i suppose).  if i click on this link, it takes me to an error page showing: 

Not Found

The requested URL /community/test was not found on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

would appreciate if anyone could tell me how to change this