sudo cp /var/lib/dpkg/available-old /var/lib/dpkg/available

Can you give the output of:

sudo apt-get update; sudo apt-get -y upgrade

Thanks

"not working" could mean a MILLION different things so tells us nearly nothing.

 TrueType core fonts for the Web EULA
 │
 │ END-USER LICENSE AGREEMENT FOR MICROSOFT SOFTWARE
 │
 │ IMPORTANT-READ CAREFULLY: This Microsoft End-User License Agreement
 │ ("EULA") is a legal agreement between you (either an individual or a
 │ single entity) and Microsoft Corporation for the Microsoft software
 │ accompanying this EULA, which includes computer software and may include
 │ associated media, printed materials, and "on-line" or electronic
 │ documentation ("SOFTWARE PRODUCT" or "SOFTWARE"). By exercising your
 │ rights to make and use copies of the SOFTWARE PRODUCT, you agree to be
 │ bound by the terms of this EULA. If you do not agree to the terms of
 │ this EULA, you may not use the SOFTWARE PRODUCT.

final message after entering given sudo commands

Then scroll down, then use TAB and SPACEBAR to accept if you agree to the terms

need to reboot

vssuresh@vssuresh-desktop:~$

W: GPG error: http://packages.medibuntu.org maverick Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 2EBC26B60C5A2783

W: GPG error: http://packages.medibuntu.org maverick Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 2EBC26B60C5A2783

sudo gpg --export --armor 2EBC26B60C5A2783 | sudo apt-key add -

[sudo] password for vssuresh: [sudo] password for vssuresh:
Sorry, try again.
ecen though my password is correct same message repeating

The password is incorrect, please be sure you have not caps-lock active then please reset your user password:

http://www.psychocats.net/ubuntu/resetpassword

update manager,tweak,nothing is working not even opening

any update on this issue?