Unable to login into admin panel of MAGENTO.

We can overcome this problem by modifying or updating the following page.

app\code\core\Mage\Core\Model\Session\Abstract\varien.php

$this->getCookie()->getDomain(),
$this->getCookie()->isSecure(),
$this->getCookie()->getHttponly()

Comment the isSecure() and save the file.

Hope from the above changes, magento admin will work now on your localhost with the following url.