To login you should enter the login and the password, which have been specified during installation. In case the entered data is incorrect, you will be redirected back to the login form.
CNStats uses cookies for authorization. Possible reasons for authorization failure may be as follows:
The additional option "Remember me on this computer" allows to skip login procedure every time you enter the system.
Note: This option should be used only for computers, to which no one else could gain access except you.
In case CNStats redirects you back to login form without any explanations, then you should check the following browser and system settings:
If there are still no results, then you should try to delete cookies.