Growing up isn't easy for a hit TV series whose wide-eyed ''teen'' cast graduates, forcing them to leave their safe, sugarcoated high school halls for edgier, alcohol-soaked college dorms. So why invite DVD audiences to relive the awkward failure of Saved by the Bell's transition from shiny, happy Saturday-morning smash to dull, immature prime-time sitcom in The College Years? Bayside High alumni Zack (Mark-Paul Gosselaar), Slater (Mario Lopez), Screech (Dustin Diamond), and Kelly (Tiffani-Amber Thiessen, who's missing from the pilot, but turns up in the opener) arrive at California U with the same dorm suite, and the cornball innocence of the original Bell. The guys get ''slimed'' during frat hazing, the roommates contemplate cheating on an exam, and Zack yells, ''Screech, you're about two seconds away from a noogie!'' (The most realistic, and funniest, aspect of the show is the early-'90s grunge fashions plaid shirts, combat boots). No wonder the series didn't see a sophomore year.