Admin Login Issue

Hello Every One,

I am new in vbulliten forums and i have facing login issue.

My client purchase a vbulliten forums and he install it on sever and it is working on sever, and he sent me one copy of that to configured locally to feature implement, and i made few changes on database and run the sql query in phpmyadmin, it configued successfully, but when i am trying to login into admin panel with username/password it redirect the page on http://localhost/vbulliten/login.php?do=login then it redirect to this page http://localhost/vbulliten/admincp/ and it didn't login into admin panel.

Why this happaning please resolve my issue. ASAP

thanks

Ashish