Have you ever downloaded trial version softwares from internet !!
Do you want their license key/activation key/..
So this tutorial will teach you how to find keys easily from google :-

Steps:-
suppose i have to find serial key of winrar .
so i will go to google.com and then type "winrar 94fbr".
and this will return results of pages containing Illegal keys !!!

How does it work :-
"94fbr" is the part of microsoft office 2000 that was released on internet that bypassed microsoft office 2000 activation.So if you type this after the name of any software ,google will list all the results related to keys of that software!!

Happy hacking!!