Garde told the club's in-house television channel on Thursday that Houllier said: "You must take the Villa job".
The former France and Liverpool boss spent a brief spell in charge at Villa Park during the 2010-11 season before falling ill.
"Gerard told me a lot of good, positive things," said Garde who was appointed on Monday. "Actually I visited him when he was manager of Aston Villa so I was not totally lost when I came here.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
"Gerard has a lot of experience with the national team and every situation in football. He's a quite open-minded person too," added the former Olympique Lyonnais coach.
"We had a spell together at Lyon and we never lost contact. When he spoke to me about Aston Villa it was all positive.
"He told me 'go on, it's a difficult situation currently but it's a big club with people who will work for you'."
Garde will be in the dugout for the first time when Villa host leaders Manchester City on Sunday.
"We have nothing to lose against City," said the Frenchman. "They are top, we are bottom. I want my players to enjoy the game, we will make it tough for them.
"I have been happy with how we have trained this week. I hope to keep Villa up, this is one of my targets of course. My main target has been to meet the players and give them confidence quickly."
(Writing by Tony Jimenez; Editing by Toby Davis)
