I downloaded angry birds on my pc. and i need to give a serial number for it,..how do i get the serial number?

Namastey!

For Windows users, go to Start, and then Run. Type in regedit and click OK. The registry will open. Search for the game's title (CTRL-F). Hit F3 to continue the search if the title doesn't show up on the first page. If you look in the data column, you may see a long string of numbers and letters that looks like a serial number. Write it down and save it.