"Security concerns" have been cited as its primary motivation for the move, according to a report in the published yesterday in the Financial Times.
A number of the Google's employees whose identities were not revealed were reported by the FT as saying Google was actively moving staff away from Windows following the hacking attacks on Google from China at the end of last year.
The attacks were thought to be connected to a flaw in Internet Explorer 6 being run on Google's Windows machines, allowing malware to access the company's computers in its Chinese offices.
Despite what could be seen as rational security concerns Windows dominates the market both in sales and in terms of being targeted by malware employees were also quoted as claiming it was an attempt by Google to push them onto its own operating system that it is thought to be developing.
"A lot of it is an effort to run things on Google product," one employee told the FT. "Before the security [problem], there was a directive by the company to try to run things on Google products. It was a long time coming."
Employees claimed that to stay on Windows, they had to gain the approval of senior executives.
Google would not comment directly on the matter. Instead, a spokesperson for the company said: "We're always working to improve the efficiency of our business, but we do not comment on specific operational matters."
Microsoft could offer no comment at the time of writing.
The cyber attack on Google which happened in December 2009 but was not discovered until weeks later was one of the most high profile in years. The company traced the attack to China and threatened to shut down all operations in the country as a result.
In March, Google disbanded google.cn and rerouted all traffic through its Hong Kong-based site google.com.hk which did not face the same censorship rules as mainland China.
China has maintained its innocence throughout.
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Jennifer Scott is a former freelance journalist and currently political reporter for Sky News. She has a varied writing history, having started her career at Dennis Publishing, working in various roles across its business technology titles, including ITPro. Jennifer has specialised in a number of areas over the years and has produced a wealth of content for ITPro, focusing largely on data storage, networking, cloud computing, and telecommunications.
Most recently Jennifer has turned her skills to the political sphere and broadcast journalism, where she has worked for the BBC as a political reporter, before moving to Sky News.
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