www.bikepedia.com Use the "Complete Bicycles and Frames" on the left menu. Specialized hasn't changed worlds on the Hardrocks, so initially you might want to key on color when looking through the years. Obviously if the bike is blue and 1999 was red it ain't right :-)

That should get you close. There's some info out there missing, like I know my daughters Trek MTB doesn't show in the list as having been available in purple/silver but hers sure is.