"Home Improvement" -- one of the top-rated sitcoms of the last millennia -- will forever be stuck in the 90s ... because one of its stars tells TMZ there is ZERO chance the entire cast will get back together again.
Fans got a mini dose of H.I. love earlier this year ... when Jonathan Taylor Thomas was a guest star on "Last Man Standing" ... reuniting him with his former TV dad, Tim Allen.
But Patricia Richardson -- who played Jill Taylor on the show -- told us a full-on reunion show is a complete impossibility because one key element is missing -- the neighbor guy Wilson, played by actor Earl Hindman.
Hindman died 10 years ago (Dec. 29, 2003) ... and, according to Richardson, so did any chance of a H.I. reprise.