Despite valiant efforts to push its Windows licensees to adopt Vista and the forthcoming Windows 7, Microsoft has one again agreed to extend the option of selling Windows XP for use on new PCs for another year, through April 30, 2010. The announcement hasn't been made publicly, but AppleInsider can exclusively report that according to a source within Hewlett Packard, Microsoft has granted the PC giant an extension to its existing rights to continue selling the nearly eight year old Windows XP on the company's business desktops, workstations, and notebooks in place of Windows 7 for another year. Microsoft isn't excited about the XP extension, as the internal communique provided by the source stated, "It’s important to remind customers that Microsoft are still planning to retire XP Pro Mainstream support on April 14th 2009 and will only provide OS security updates beyond that date unless the customer has an Extended Hotfix Support contract. MS Extended Support for XP Pr...