First off it pays to back up all software and files and keep a note of product keys etc just in case of theft or crash and burn. I am sure you have learned this lesson now.
Sad that the company is less than helpful to you...most companies can tie in product registration with an email addy and unlock/reinstate your product key.
I have not used PC drummer but have used many other drum progs. When choosing any such prog many things should be considered. A lot is down to personal preferences, the application and style of music you want to play, cost, the users skill level and knowledge and what is available. First thought is to go with what you know and what works for you. That said maybe it is time for a change and upgrade.
Toontrack EZ drummer is pretty good.
I would also recommend Addictive drums. These software progs are a bit more expensive than PC drummer or what you may want to pay but are well worth the extra.


http://www.soundclick.com/bands/songInfo.cfm?bandID=687727&songID=5238055