Zaha departed Selhurst Park for United for an undisclosed fee ahead of the 2013-14 campaign.
However, the 21-year-old, who has represented England on two occasions, endured a frustrating debut campaign at Old Trafford and was shipped out on loan to Cardiff City for the second half of last season.
New United manager Louis van Gaal could not guarantee Zaha regular first-team action and he subsequently returned to Palace on loan last month, scoring a dramatic equaliser on his second debut in a 3-3 draw at Newcastle United.
Despite his United career failing to take off, Zaha has not given up hope of being a success at the club and stated his desire to once more feature for his country.
"The goal is to do my best here for the season and go back and make sure I get back into the team and the England setup," Zaha said.
"It is just great to be playing again. There is nothing like being out on the pitch and the crowd singing your name.
"It was a bit frustrating [at United]. What am I doing if I am not playing?
"I know how everything works here and the gaffer [Neil Warnock] just wants to give me game-time and wants me to improve so I am just glad I am back."
Zaha admits leaving United on a permanent basis had crossed his mind.
He added: "I thought about leaving for a while.
"Then I thought: 'Let's stay and prove how I can play to the new manager'. He felt it was best for me to go on loan and it was best for me to come home."
