The Pentagon, the National Security Agency, and private organizations have developed security standards and a software program to help users of Microsoft's Windows 2000 configure their computer systems for maximum security against hackers and thieves.

Similar solutions for other operating systems will be coming soon, government officials said. The standards and software are available free to anyone who wants to use them.

The government's software program probes computers for known security flaws and makes suggestions on how to eliminate holes used by hackers.

The unprecedented effort is expected to have immediate impact. All Defense Department computers have to meet the standards immediately, and the White House is considering requiring the rest of the federal government to follow suit.

Experts say the keys to success will be extending the standards to school, business, and home users, making the security principles simple enough for the public to understand, and ensuring that the security software stays ahead of increasingly sophisticated computer attackers.

"If it's just government, it won't have as much value as it will if it's government and the private sector," said Richard Clarke, President Bush's computer security adviser.

The government's partners in the private sector intend to broaden the security standards to other operating systems, including those Windows products most commonly used at home.

Maintaining the security of home computers is "a massive problem," said Clint Kreitner, head of the Center for Internet Security (CIS), a nonprofit partnership of companies and American and Canadian government agencies. "[Consumers] slap their systems on the net and get ready to go, then wonder why they get breached in the next 10 minutes."

The effort has brought together some of the biggest names in business, including computer chipmaker Intel Corp., Chevron, and Visa—part of the group that helped create the standards and is encouraging their use.

Microsoft, which is embarking on its own efforts to make its software more secure, has reviewed the standards and made suggestions.

The standards have developed slowly, in part because security in the past frequently has been handled through technical security bulletins written for engineers.

"You'd give a 200-page document to a system administrator, and say, 'Have a nice day'," Clarke said. "So no one did it."

The breadth of the problem is staggering. The technology research firm Gartner recently projected that through 2005, 90 percent of computer attacks will use known security flaws for which a solution is available but not installed.

Most recent attacks were written and released by bored kids testing their skills, officials said, but the government is becoming more concerned about organized attacks against federal computers from terrorists or foreign governments.