Follow the below simple steps to Upgrade Ubuntu using command line:

1. Open Terminal.

Applications -> Accessories -> Terminal

(or)

Ctrl + Alt + t

2. Enter the below comment to update ubuntu

sdexperts@ubuntu:~$ sudo apt-get upgrade
[sudo] password for sdexperts:*********

3. This will update ubuntu.

Its very simple to refresh your IP. Just follow these below steps.

I will tell you how to refresh your IP address on a network. This will only repair internet connection problems if you’ve changed locations and you can’t connect to the Internet. This is only for Windows machines.

Steps:
1. Open the Command Prompt (from the Start button, go to Programs > Accessories > Command Prompt).
2. In the command prompt window, type “ipconfig /release”
3. In the command prompt window, type “ipconfig /renew”
4. Exit the Command Prompt by typing “exit”

Tips:
* You may want to create a small batch file of this command. See How to Write a Batch File.
* To check your IP address, type “ipconfig”
* To check detailed information about your TCP/IP settings, type “ipconfig /all”
* Win98 users should type ipconfig /renew_all

Warnings:
* After completing your ‘ipconfig /renew’, check what IP address you have by ‘ipconfig’. If you have an IP address starting with 169.254, then you are not connected to the Internet. Addresses starting with 169.254 are assigned automatically by Windows when Windows is unable to contact an Internet (DHCP) server for an address.