Financial Times reports that Google will no longer use Windows internally because of security concerns.
"The directive to move to other operating systems began in earnest in January, after Google's Chinese operations were hacked, and could effectively end the use of Windows at Google, which employs more than 10,000 workers internationally. New hires are now given the option of using Apple's Mac computers or PCs running the Linux operating system. Employees wanting to stay on Windows required clearance from 'quite senior levels,' one employee said. 'Getting a new Windows machine now requires CIO approval,' said another employee."
In January, Google explained that "in mid-December, we detected a highly sophisticated and targeted attack on our corporate infrastructure originating from China that resulted in the theft of intellectual property from Google". The attacks used an Internet Explorer vulnerability and Microsoft said that they mostly targeted Internet Explorer 6.
It's strange to see that a cyber attack was one of the main reasons for closing Google's Chinese search engine and for no longer using Windows at Google. Most likely, Google intends to test Chrome OS internally and one of the most interesting things about Chrome OS is that it's very secure.