<P> The show went through many cast changes, the first major change being the unexplained departure of Sabrina's best friend Jenny Kelly (Michelle Beaudoin) at the end of the first season . </P> <P> At the beginning of the fourth season, Valerie departs the show permanently along with Libby . Valerie's character moves away to Alaska with her family, while Libby transfers to a boarding school . </P> <P> When the series finished its fourth season, several secondary characters left the show, including Martin Mull and Nate Richert . Richert, who played Sabrina's boyfriend Harvey since the first season, was cut in order to give the show a more "grown - up look" as Sabrina was about to attend college . The decision was later rescinded, and Richert appeared in three episodes of season five and then returned as a series regular in season six and seven . </P> <P> After the series' sixth season, Caroline Rhea and Beth Broderick, who portrayed Sabrina's aunts from the show's premiere, decided to leave the show . When the character of Sabrina started to attend college, the role of her aunts became less important . Broderick felt that the role of Zelda had nothing more to offer, while Rhea landed her own syndicated talk show, The Caroline Rhea Show . </P>

When does harvey come back in sabrina the teenage witch