How do you play cracked games online

[mrc213]

See ill explain to you my problem a bit more basically my friend bought me a game and i tryed it out 6 days ago although my friend bought it for me a month ago when i tryed to go online it said something like i don't got a legit cd key to go online so now i got this game and tryed to take it back but they wouldnt let me and now im stuck wanting to know how can i go online with a game that has a non legit cd key also i wanted to know how does punk buster work and how do i make a no cd exe and what kinda sites can i find more info on this subject and i just really wanna know how to play a cracked game online cuz u know google hides it from u and given my situation i need help cuz im a newbee at this plz help me and thnx for all the help