Google, in its attempt to challenge Microsoft's PC dominance, has moved up the market entrance of its cloud-based Chrome operating system from 2011 to late fall, less than six months from now according to reports out of the Computex show in Taiwan quoting Sundar Pichai, the Google VP in charge of the Chrome project.

He said Google expects the OS to be "widely adopted across the netbook sector" and "reach millions of users on day one."

Reuters said Microsoft last Thursday compared Chrome to the early days of the PC when applications had to be written to specific boxes because netbook vendors are going tinker with the open source Chrome code.

Pichai denied the allegation claiming similarities in the base core would allow applications to run on all Chrome machines. He also told Reuters that "Chrome OS is one of the few future operating systems for which there are already millions of applications that work."

Interfaces are also expected to vary.

Penetration of the Chrome browser on which the operating system is based hit 7.05% worldwide in May according to Net Applications. It was down a half-a-percent in the U.S. to 4.51% from 4.97% in April. Google has claimed 70 million people are using the browser.