Can you add a domain user to the site settings?

R: yes, i add the user (ex:domain\ituser) that i logged in other computer of that domain to test to enter on browser. but is allways ask for a user and password. I put the "domain\ituser", but don't let me enter on SSRS

All I have to do is log in as a builtin administrator and grant access to the user by adding domainname\username and then grant the appropriate access.

R: is not working for me, is needed to create any user on SQLserver security->Login ?