United ended the current campaign 22 points behind champions Manchester City in seventh place, their lowest finishing position since 1990.
But Van Gaal believes the instant success he experienced at Barcelona and Bayern Munich can be replicated at Old Trafford.
“They are hoping I can do it in my first season. I did it in Spain and I think I can do it in England too,” said the 62-year-old.
“I have always had a winning mentality and will find a system to make sure we are not beatable.”
Van Gaal will not leave his current position as Holland boss until the end of this summer’s World Cup. But the Dutchman feels United will not be disadvantaged by his late arrival, having already put plans in place for the new season.
“I’ve already talked a lot with the bosses. They already know the names of the players I would like to have, but also those who are allowed to leave,” Van Gaal added.
“I’ve never dealt with transfers and I’m not going to start now, just to say which players I want to have and what players can go. I don’t discuss money.”