The public beta for Microsoft's anti-virus tool, codenamed Morro, will launch on Tuesday.

Redmond's replacement for Windows Live OneCare is to be called Microsoft Security Essentials, and will run on Windows XP, Vista, and Windows 7.

According to Microsoft, the software will use a signature-based detection system, and will include anti-rootkit technology, as well as facilities to reduce resource requirements such as CPU throttling scanning when idle, smart caching and active memory swapping. Initial reviews of Security Essentials point to a very slimline install, potentially making the new player a hit with netbooks, ultraportables, and older machines.

Although the product is aimed at the consumer market, it is likely to be attractive to many SMEs, and potentially larger organisations looking to cut costs on desktop AV licences. However, competitors in the AV space have been bullish, pointing to the lack of additional applications such as firewalls, spam filters and encryption commonly found in desktop suites.