Microsoft is launching its own brand of home security software to protect Windows PCs from hackers, viruses, spyware and other net threats.
The software giant will unveil the OneCare Live service in June in the US.
The move puts Microsoft in direct competition with well-established companies such as Symantec and McAfee.
The Windows operating system has long been a favourite of virus writers, malicious hackers and other hi-tech vandals because it is so widely used.
The launch of OneCare Live is the latest result of Bill Gates' declaration in January 2002 to make Windows more secure.
In September 2004 Microsoft released the SP2 update for Windows XP which introduced a security console that users could use to check the status of their anti-virus software, firewall and Windows updates.
In the past few years it has also bought some security companies and has used their software as the basis for the new service.
In 2005 Microsoft began offering its own-brand anti-spyware software and recruited users to test out its creation.
Users will be able to get hold of OneCare Live in shops or via the web. It will roll together a firewall as well as anti-virus and anti-spyware programs plus backup and computer maintenance tools.
The package of programs will cost $49 for a year's subscription. Prices and launch dates for the rest of the world have not yet been announced. Up to three computers can be protected with the software.
Those Americans keen to test the service can sign up in April and get a year's subscription for $19.95.
In launching its own-brand anti-virus and security products Microsoft will be taking on firms that are firmly established brands in home security software such as Symantec, McAfee, Trend Micro and many others.
Earlier this year Symantec declared its intent to produce an all-in-one software package of security software called Genesis in late 2006.
However, Microsoft said its package of products was intended for those Windows users who do not update their protections or have no security software installed at all. Microsoft claims that 70% of Windows users fall into this category.