Backup & Restore installed package.

to backup packages
1. sudo nautilus
2. copy from /var/cache/apt/archives/* to Desktop/inst_packages

Run in terminal
sudo dpkg –get-selections > ~/Desktop/inst_packages/myPackages

To Recover packages
1. sudo nautilus
2. Paste backup packages to /var/cache/apt/archives/
3. Run in Terminal
sudo dpkg –set-selections < myPackages && sudo apt-get dselect-upgrade