Consumers shouldn't be worried that Microsoft Corp.'s new security technology will wrest control of their PCs and give it to media companies, Bill Gates said Tuesday. They can always choose not to use it, he said.

The Microsoft co-founder expects consumers, as well as governments and businesses, to embrace the system, which hard-wires security into silicon chips rather than just software. It's designed to offer unprecedented levels of protection against hacking and eavesdropping.

"This is a mechanism that if people want to use, for example, to protect medical records, they can use it," Gates said. "It's a lot of work to do this stuff, and we think consumers will want those privacy guarantees. If they don't want them, then fine, ask me about our other work."

The technology has raised eyebrows not only for the absolute control it would grant such creators of digital content as music and movie companies but also because it is being driven by Microsoft, which has a reputation for strong-arming the computer industry.

Gates spoke about the technology, known as the "Next Generation Secure Computing Base," at the 12th Windows Hardware Engineering Conference.

In the first demonstration of how the system would work, the company showed how programs protected by the technology could not be altered or their communications intercepted by a malicious hacker, who was played by a Microsoft worker dressed in a red T-shirt adorned with a skull.

But the demonstration was limited to attempts to rewrite simple programs and capture chat-room traffic. Many of the functions that will be built into hardware were emulated by software because the chips are not yet built.

The final version is expected to offer more control. Creators of top-secret government documents, financial records or other sensitive material could assign rights to sensitive files, allowing them to be viewed only on trusted computers running the system. Anyone else would be locked out.

The same platform could be employed by content creators, who include software makers like Microsoft. They could severely limit how materials are copied or even how long they last -- a stark contrast from today's computers.