Microsoft boss Bill Gates has told a group of influential bloggers that copy protection for digital music and video is too complex for consumers.
Microsoft's new Zune has DRM on all Zune store tracks
Mr Gates was speaking to an invited party of bloggers and web developers at Microsoft's Seattle headquarters.
Digital Rights Management (DRM), which is used to stop copying, is a big issue for some people who feel it limits what they can do with legally bought files.
"DRM is not where it should be," said Mr Gates, reported blogger Steve Rubel.
"In the end of the day incentive systems (for artists) make a difference," said Mr Gates.
"But we don't have the right thing here in terms of simplicity or interoperability," he added.
His comments were reported on the Micro Persuasion technology blog, and the visit was blogged by the other attendees.
Microsoft is one of the biggest exponents of DRM, which is used to protect music and video files on lots of different online services, including Napster and the Zune store.
Blogger Michael Arrington, of Techcrunch.com, said Bill Gates' short-term advice for people wanting to transfer songs from one system to another was to "buy a CD and rip it".
Most CDs do not have any copy protection and can be copied to a PC and to an MP3 player easily and, in the United States at least, legally.
In the UK it is illegal to make personal copies of CDs, although the music industry has made clear it will take no action against people copying their legally bought CDs to their computers or music players.
Critics of DRM argue that the tools limit the value of downloaded music or video files because of the restrictions imposed to try to prevent copying.
They say that DRM is routinely circumvented and that different competing standards cause confusion for consumers.
Suw Charman, of the Open Rights Group, said it was a "bit rich of Bill Gates to make his comments given how much DRM is stuffed into Windows Vista", the new operating system from Microsoft.
"The problem with DRM is that it is very anti-consumer," she said.
"It is bully-boy tactics by the media industry," she added.
But backers of DRM argue it gives artists an assurance that their work is being protected.
Ms Charman called for more information for consumers when they buy digital files and CDs.
"Often consumers do not know what restrictions have been imposed on CDs or digital music until after they have bought them," she said.
She added: "Apple have been known to change the rules after people have bought tracks."