The Welshman was placed in temporary charge at Old Trafford on Tuesday after the Premier League champions dismissed David Moyes 10 months into his six-year deal following a disappointing first season at the helm.
United legend Giggs is not thought to be among the leading contenders to take the role on a permanent basis, but he will assume control for at least the final four games of the season.
"I'd like to go on record to thank David for giving me my first chance in coaching, it's something I'll always remember when he rang and asked me to come on board. He gave me the opportunity for my first coaching role," he said at a press conference on Friday.
"I'd like to say how proud I am to take charge for the remaining four games. It's the club I've supported all my life and been associated with for 25 or 26 years.
"I've enjoyed the week, I'm proud more than anything, it's probably the proudest moment of my career.
"I'll enjoy the last two and a half weeks of the season and bring back some smiles on the faces of the fans and look forward to the game, just like a player really."
He added: "I'm just concentrating on the four games, including tomorrow against Norwich which is a tough game, they're fighting for their lives."
"I've just give myself a new five-year contract," he said "I'm using my power while I can. I haven't done much this week but I'm still involved as a player.
"I've trained okay this week but the lads have looked sharp. There are 20-odd players involved with a shout."
