Citing several Google employees, the FT said the decision to move to other operating systems including Apple Inc's Mac OS and open-source Linux began in earnest in January after Google's Chinese operations were hacked. Internet security firm McAfee Inc said at the time the cyber attacks on Google and other businesses had exploited a previously unknown flaw in Microsoft's Internet Explorer browser, which was vulnerable on all recent versions of Windows. The FT quoted one Google employee as saying: "We're not doing any more Windows. It is a security effort." Another said: "Getting a new Windows machine now requires CIO (chief information officer) approval." Google said in a statement: "We're always working to improve the efficiency of our business, but we do not comment on specific operational matters." Google, which already offers e-mail, Web and other software products that compete with Microsoft's offerings, is developing its own operating system based on its Chrome browser. It will initially target netbooks, or inexpensive, pared-down notebook PCs. Microsoft Windows runs about nine out of 10 of the world's personal computers.