Microsoft has another barrier to cross in China in order to grow the market share for Windows 10. Although the company is giving free updates to existing Windows 7 and Windows 8 users, a large number of personal computers in China still run the 14-year-old Windows XP which Microsoft stopped upgrading a year ago.

More than 41 percent of the computers that have been connected to the Internet over the past three months were running Windows XP, according to Baidu Inc, the biggest search engine provider in China.

The market share for Windows 7, which Microsoft has decided to shutter eventually, reached 46.7 percent in the same period, said Baidu.

Cao said the desire for Chinese users to transfer from XP to Windows 10 will be very weak in the short run.

"A large number of XP users use a pirated OS and hence would opt for a pirated version of Windows 10 even if they decide to upgrade," Cao said. "In addition, the two OSs have remarkably different ways of use and the learning costs for XP users will be relatively high."

What to watch out for in the new OS

Cortana

A built-in voice assistant tool for Windows 10 users. Cortana is capable of helping users take notes, check weather and send e-mails. Using Microsoft's cloud service, the assistant can bring information to different Windows devices. Cortana understands a long list of languages and the correction rate is impressive.

It is a strong competitor for Apple Inc's Siri in terms of what they can do and how well they do it. However, Microsoft should put a deep think on how to keep users interested in a voice assistant tool. How often do we use Siri nowadays?

Multi-tasking options

On a Windows 10 tablet, users can open two and even more applications at the same time. The iOS only supports single-task operations, meaning one must repeatedly turn on and off different apps in a multi-task scenario.

But Windows 10's multi-functions require time to master and are not ideal for first-time users.

Windows Hello

A device authentication system, Windows Hello allows users to access different devices using fingerprint, face, or eye recognition. No need to type in passwords when unlocking your devices.

The bad news is Windows Hello is only available on devices that are equipped with the authentication components, and such devices usually come with a higher price.