Microsoft has officially announced plans to exit the paid-for antivirus software market, killing off the Windows Live OneCare product it launched just two years ago.  Windows Live OneCare will no longer be available from June 2009, at which time Microsoft will offer a free antivirus product, called Morro, to Windows users. The company said the free security software would help encourage more people to take antivirus seriously, claiming nearly 50 percent of Windows users don't have an antivirus tool installed on their PC. However, Morro, which is expected to run Windows OneCare's antimalware engine but will use fewer system resources, won't be bundled into the operating system, Barzdukas said. That decision could help placate concerns from security software vendors, whose ability to sell antivirus products to consumers would be hampered if Microsoft bundled a free tool with its operating systems. Morro is also expected to be a low-end security tool - it will provide protection from viruses and Trojans, but will not include the systems management and backup capabilities.