Microsoft has launched a trial version of its upcoming anti-virus suite in the US, China, Brazil and Mexico.
According to the company, Security Essentials is intended to provide basic defence against viruses, trojans, rootkits and spyware. However, it stressed that it is not an alternative to full security suites, describing its offering as a "core level of protection".
The software was first detailed in November 2008 following the announcement that Microsoft was ending support for its premium security suite Live OneCare.
Speaking at the time, Microsoft's senior director of product management Amy Barzdukas said that Security Essentials was designed to cut down on the numbers of unprotected PCs, rather than compete with vendors such as Symantec, McAfee and AVG.
"We know that there are still some 60 per cent of consumers in developed markets and even more in emerging markets, that don't have up-to-date security protection on their PCs, and we wanted to help provide that core level of protection," she said.
Microsoft has not announced when the software will be available in the UK.