Magento admin login not working in chrome but works fine for firefox?

I think there is the problem with session cookie with the chrome browser. So just go through this directory /app/code/core/Mage/Core/Model/Session/Abstract/Varien.php file and comment out the line from 85 to 92 in magento (1.7.2 for my case). Like this

    // session cookie params
   /* $cookieParams = array(
        'lifetime' => $cookie->getLifetime(),
        'path'     => $cookie->getPath(),
        'domain'   => $cookie->getConfigDomain(),
        'secure'   => $cookie->isSecure(),
        'httponly' => $cookie->getHttponly()
    );
  */
after that try to make login from your backend. Hopefully you can make login with chrome.