Software giant Microsoft said it will release a beta test of its free computer security program next week and is on track to launch a finished product in autumn.

Microsoft Security Essentials is a bog standard AV product that claims to find and kill malicious software that can steal passwords and other personal information or turn PCs into spam distribution hubs. Redmond has promised to upload updated lists of identified malware

daily, but will keep a low profile unless it detects dangerous software. Theresa Burch, a director on the security software team, said the program tries to spot malicious software even if it's not on the list of known corrupters. When it encounters something suspicious, it phones home to Microsoft server for updated intelligence before allowing the program to run, a process Burch said is almost instantaneous.

Microsoft will also have a list of trusted software sources, so the tool won't accidentally block items like Google Web browser toolbar, she said. Security Essentials could put the fear of God into McAfee and Symantec and several other free packages. Burch said Microsoft was not interested in knocking such people out of business but instead wanted to improve security overall by people who don't have current antivirus software to protect their PCs.

The security software will come as a free download, but it won't be part of Microsoft's Windows 7 operating system, which goes on sale in October. Bundling the two could be fodder for antitrust complaints.