The new product, codenamed Morro, will be known as Microsoft Security Essentials, and 75,000 beta versions will be available today.
The software will attempt to protect Windows users from viruses, spyware, rootkits and Trojans, going head-to-head with a range of AV vendors, from Symantec and McAfee through to AVG and Eset.
The product is aimed at home users and developing countries that currently have no security software installed at all. It is thought that these machines make up the bulk of many of the world's botnets and other distributed online threats.
However, if the software proves robust, SME interest is guaranteed, and it's certain that the market incumbents will be watching this beta with interest, if not concern.
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