Steam Keygen Review Can I Use The Same Key Code/ Keygen For "Left 4 Dead" Game?

Can i use the same key code/ keygen for "Left 4 Dead" game? - steam keygen review

Hello, I have a brief question and would just like to know if this will work. My friend recently bought a "Left 4 Dead, and you have installed on your computer to play online. I just wanted to know if it will be possible for me to play online on my computer and install it using the same code key / keygen. I already have Steam installed to play on my PC (CS & Team Fortress 2) wonder what will be added to my game and work ?...... thank you.