America Online Inc. is releasing a new version of its software today that focuses on increasing online safety and security, which the company hopes will help it hold on to more subscribers.

Dubbed AOL 9.0 Security, the latest version of America Online's software will give dial-up and high-speed subscribers free McAfee antivirus software and automatic upgrades. Previously, AOL had charged $3.95 a month for upgrades.

"Safety and security is now the number-one issue facing our members, and we want them to have the greatest peace of mind as they get onto AOL," said Danny Krifcher, an America Online executive vice president. "Most people have virus protection software but don't have it updated. By including automatic updates, we are keeping our members updated and protected all the time."

The debut of the new software comes as the Dulles-based Internet firm continues to lose subscribers to competitors offering faster or cheaper services. AOL's advertising revenue has increased recently, but the company continues to lose hundreds of thousands of subscribers each quarter.

The new emphasis on security follows a successful effort by AOL over the past year to combat spam, commercial e-mail messages that once cluttered the in-boxes of its more than 20 million customers. The company attacked the problem with new filters, lawsuits and by lobbying for new anti-spam legislation.

Krifcher said the new version of AOL would also do a better job of fighting the growing problem of spyware, hidden code that can secretly collect personal information or monitor a computer user's Web travels. Such software often latches onto people's hard drives without their permission when they download free screen savers, swap music files or use other Internet features.

Krifcher said the company plans to continue to increase the security features in its software over the next year.

"This is not the end. This is the beginning," Krifcher said.

Joe Wilcox, a senior analyst with Jupiter Research, said AOL's decision to beef up its security features follows an earlier move by Microsoft Corp.'s MSN online service to increase virus protection for its users. However, he said the company's emphasis on fighting spyware may ultimately prove to be more significant.

"Recently one of my daughter's friend's computers had been infected with spyware, and it all started with someone downloading a horoscope program," Wilcox said. "We found over 350 spyware traces. The worst of it was pop-ups launching for advertising purposes, but it had taken such a strong hold of the computer that it made the computer unusable."

In a statement, AOL chief executive Jonathan F. Miller said the new version of AOL's software should protect subscribers against these kinds of spyware disasters on their personal computers. "The Internet is a wonderful place . . . but our work won't finish until our members get everything they want out of it, and less of what they don't want."