The United manager has reached out to the club's supporter to reassure them that he will work tirelessly to ensure lessons are learnt from a turbulent first season in charge since succeeding Alex Ferguson.
United are 12 points adrift of fourth place in the Premier League and appear unlikely to qualify for the UEFA Champions League next term, a stark contrast to when United eased to the title last May.
West Brom, Everton, Newcastle United, Tottenham and Swansea City have all won at United in 2013-14 in all competitions, with Fulham, Southampton and Chelsea leaving with draws.
And Moyes is determined to make the club feared again on home soil.
"Over the years you have seen great winning sides here and, in time, I have absolutely no doubt that we will see great winning sides here again," said Moyes in the letter.
"A big step towards that will be transforming Old Trafford back into the fortress it has long been renowned as, and we will do everything in our power to get the positive performances and results to do that, so that we can give you season ticket holders and all of our supporters something to shout about."
United start a crucial run of March fixtures at West Brom on Saturday before facing Liverpool and Manchester City in the Premier League, as well as welcoming Olympiacos to Old Trafford hoping to overturn a 2-0 deficit in their UEFA Champions League last-16 tie.
Added Moyes in the letter: "Everywhere we turn people outside the club have a lot to say about Manchester United, but we have all stuck together through some tough times this season and I firmly believe that, in the long run, we will all come out at the other end, stronger for the experiences.
"Everything we need have been through will make us a better, stronger team and club in the future."
