scan any computer for open ports

Download a software called Advanced Port Scanner by simply searching in google
run this software
In select Ip textbox insert your friend's pc's IP
Do not select the range option
Scan the given IP
In 10 seconds it will give u the result and will show all open and closed ports in ur friends pc
That's it
It has done its work now it's your turn
Attck the pc through the open ports.