Apple co-founder Steve "Woz" Wozniak believes operating systems are not as easy to create as they once were.

He says: "Operating systems have got to be very radically different or come from a very different angle."

He discussed Apple's 25-year history during an interview with US TV channel, CNBC. In the interview, conducted to mark the recent 25th birthday of Apple Computer, he discusses computers in education and the prevalence of computers.

On the early days of computing, Woz says: "We went through a little period of magic and everything in the world was just so fun and exciting, and changing and different and new every day."

He looks back fondly at those days: "We have lost those days when we had to create our own little programs, and everything we did was new and the first ever. Now everything is already done, and you just use a program like a million other people."

Wozniak also reveals his belief that peer-to-peer file sharing groups, such as Napster should be "regulated".

Apple was 25 years old on April 1.