Gates said Microsoft will offer software to detect malicious applications and that the company will keep it up-to-date on an ongoing basis. He did not say when the software would be available or whether Microsoft would charge for it.
Although progress is being made against spam and viruses, Gates said the adware and malware problem is getting worse.
"This malware thing is so bad," he said in a speech at the Computer History Museum here. "Now that's the one that has us really needing to jump in."
It's also a problem that has affected Gates personally. He said his home PCs have had malware, although he has personally never been affected by a virus.
"I have had malware, (adware), that crap" on some home machines, he said.
Gates' comments came at the end of a busy Bay Area tour. Earlier Friday, Gates addressed a group of engineering students at the University of California at Berkeley.
Microsoft has been testing a for-fee antivirus product, though the company has not announced details of how it will offer it. The company purchased Romanian antivirus firm GeCad in 2003.
A Microsoft representative did not immediately have further details on the company's plans.
Another looming problem, Gates said, is the password.
"People hate changing their password," Gates said. "They pick very guessable passwords."
The industry will have to move to smart cards or some kind of biometric recognition for authentication.
"It will take five or six years," he said. "There's no doubt that has to come."
