1.) Go to this link to download it http://game.giveawayoftheday.com/mahjong-suite-9/
2.) After you download the game, click the Help menu and click "Activate Mahjong Suite" it will ask for name and Activation code.
3.) To get the activation code, go to this page http://www.mahjongsuite.com/sp/gotd/mahjong_suite__game_giveaway_of_the_day.htm.
4.) Enter your name and address, they will give you the activation code. Keep this page open.
5.) Now go to the Mahjong game in your PC and after applying the step 2 above, enter the name (not your name) "Giveaway of the day, 08 April 2012" without the quotes and the activation code number you were given after you enter the details in the above link.