Updated with the latest anti-virus software.

Network Associates will unveil technology this week that it said will revolutionize the process of keeping computers updated with the latest anti-virus software. The security firm_s McAfee division will launch its ActiveShield service through its McAfee.com Web site, which will deliver anti-virus software updates to users_ computers whenever they are connected to the Internet. Anthony Kim, manager of McAfee Clinic, said the software has the potential to limit the damage caused by such outbreaks as the Melissa virus, because users will receive fixes as soon as they are available. The ActiveShield software pings the McAfee server daily to check for software updates, patches or fixes. It gives the user the option of downloading and installing the fix, or doing it at a later date. McAfee will price ActiveShield at $39.95 for a yearly subscription. But, for a limited time, it will be $19.95.