Is there any solution for this? Yes. Solution exits :P :) Solution is as given below.
Open the terminal.(Applications-->Accessories-->Terminal)
Paste the below code.
sudo gedit /usr/share/polkit-1/actions/org.freedesktop.devicekit.disks.policy
New windows will pop up. Search for
<action id="org.freedesktop.devicekit.disks.filesystem-mount-system-internal">
<description>Mount a system-internal device</description>
<description xml:lang="da">Montér en intern enhed</description>
<description xml:lang="de">Eingebautes Gerät einhängen</description>
<message>Authentication is required to mount the device</message>
<message xml:lang="da">Autorisering er påkrævet for at montere et fil system</message>
<message xml:lang="de">Zugriffsrechte werden benötigt um das Gerät einzuhängen</message>
<defaults>
<allow_any>no</allow_any>
<allow_inactive>no</allow_inactive>
<allow_active>auth_admin_keep</allow_active>
</defaults>
</action>
Here, u can see auth_admin_keep. Just replace "auth_admin_keep" by "yes"(without double qoutes). And save the opened file.
After this, u can mount harddisk drives without entering password. Isn't this simple and easy? :P :)