After a goalless draw with Cambridge United at the end of January, United made no mistake in their fourth-round replay on Tuesday night as goals from Juan Mata, Marcos Rojo and James Wilson booked a meeting with Preston North End.
And Van Gaal, who prioritised success in the competition before kick-off, believes his team are in a great position.
"We have a real chance now, we are the highest qualifed team in the FA Cup," he told reporters. "Our status is the highest club. People are maybe betting on us. I'm not allowed... I'm not a casino man.
"Of course I think that the highest qualified teams have the highest possibilities to win than lower, but Arsenal is still in the cup, and is also a very high competitor, Liverpool is also there, we will see tomorrow, Bolton Wanderers is not so easy.
"For the club, the fans and the coach and my staff, we want to win a title this year. The biggest chance is the FA Cup, but we still have to win four games to do that.
"Tonight, I don't think we played a very good match. But it is always difficult against a defensive team. We could have done better but I am pleased with the result."
Cambridge boss Richard Money left Manchester in positive mood, but admitted that victory was always unlikely for his side even if Tom Elliott had converted his gilt-edged opportunity in the very first minute.
"I thought it [Elliott's shot] was in," he told BT Sport. "It probably wouldn't have made any difference, but he has done everything right.
"It was a good chance, not sure how much more he could have done.
"I think 3-0 is par for the course. We walked off the pitch with our pride intact.
"In the second half we have done ourselves proud. We gave everything we wanted to give, we have got to use it to keep going as a team and football club."
