Gary Ablett was hit with a double injury blow when both Johnny Mullins and Paul Huntington were unable to start against the promotion-chasing Terriers.
Mullins suffered a reaction on Thursday to the back injury that kept him out of last Saturday's game at Leyton Orient whilst Huntington was unwell.
Andy Halls continued to deputise for Mullins with Danny Swailes, who missed the Orient game, returning to replace Huntington. Same Barnes lined up alongside Swailes to make his home debut.
Ablett made one further change with Richie Partridge being preferred to James Vincent.
The Hatters got off to the worst possible start when they fell behind inside 90 seconds when Anthony Pilkington's low shot took a deflection off Barnes to wrong foot Fon Williams.
Anthony Kay shot wide as Town pressed for a second. And Fon Williams made a brilliant save to deny Pilkington a second after 12 minutes.
From the restart Jabo Ibehre had the County fans out of their seats when he turned on the edge of the box and shot just over.
Jemal Johnson then found Mat Sadler in the box who slipped just as he was about to cross.
Fon Williams was called into action again on 25 when he got down well to save from Jordan Rhodes.
And ten minutes later the Welshman denied the former Ipswich striker again with another terrific save.
Eight minutes before the break the Terriers controversially doubled their advantage. Facing his own goal David Perkins seemed to be clipped by Danny Drinkwater, the ball broke to Theo Robinson, who looked well offside, and he easily beat Fon Williams from close range.
The second half was one way traffic although it took Town until the 68th minute to add to their scoreline. Pilkington raced past Partridge and crossed from the left. Barnes deflected the ball onto the post and the rebound fell perfectly for Jordan Rhodes to tap home.
Halls cleared a Roberts's effort off the line before the Terriers added a fourth five minutes from time when Danny Drinkwater curled home a 20-yard free kick.
County forced Alex Smithies into his fist save two minutes later when he got down to gather Donnelly's low drive.
Huddersfield weren't finished, though, and added two more in stoppage time. Roberts curled a beauty over Fon Williams and then Lee Novak scored from the spot after Barnes had brought down Drinkwater.
The defeat equalled County's worst ever here at Edgeley Park when Peterborough United won by the same scoreline back in 1961.
