Murray lost the 2012 final to the Swiss in their last meeting at Wimbledon but did beat him in the Olympic final at the All England Club in the same year.
"I feel like I'm playing better tennis than I was then," said Murray, who won the title at SW19 in 2013.
Defending champion Novak Djokovic plays Richard Gasquet in the first semi.
A lot has happened to Murray in the three years since he choked back the tears on Centre Court after a four-set defeat to Federer.
The Scot from Dunblane has won two Grand Slam titles and one Olympic gold medal, while Federer has not had major success since.
Murray, who became the first British man in 77 years to be crowned Wimbledon champion, is in his sixth All England Club semi-final and 17th at the majors.
"I hope I get good support on Friday," Murray said. "It's been the case throughout the whole event and every year that I played here. Roger's extremely popular everywhere he goes, so it might not be as partisan a crowd or atmosphere as some matches that I play here. But it will still be an excellent atmosphere. I'll still get a boost from the crowd, I'm sure".
