Microsoft will be launching a subscription-based security program that it hopes will protect PCs and optimise performance.

Dubbed OneCare the service is currently being trialled by Microsoft employees and should be available by the end of the year.

OneCare provides antivirus support, anti-spam filtering and firewall protection, automated hard drive cleaning and back-up, and an update notification service.

"Windows OneCare is the next major advance in our ongoing efforts to help keep consumers' Windows-based PCs 'healthy' in a way that's simple and as worry-free as possible," said Ryan Hamlin, general manager of Microsoft's Technology Care and Safety Group.

"We are designing the service so that it will continually update and evolve over time, helping to ensure that our customers have the most complete and effective protection and safety services in place every time they turn on their PC."

Microsoft has been promising to deliver an antivirus offering for the past year and acquired antivirus firm Sybari in February.

No pricing details have yet been released. This is the first time that Microsoft has tried to run a subscription service rather than charging a one-off licence fee.