Microsoft is working on an update for Windows 8 operating system (OS) under a code-named Blue, which is planned to be released later this year.

The updated version of the OS, is anticipated restore start button that had been familiar to users, which was removed from the new version, according to Bloomberg.

Chief of Windows engineering Julie Larson-Green said that the preview version of the new OS will be available at Microsoft’s Build conference in June.

Microsoft Windows and Windows Live corporate vice president and chief financial officer & chief marketing officer Tami Reller said the Windows Blue update is also an opportunity for the company to respond to the customer feedback being closely listened to since the launch of Windows 8 and Windows RT.

"From a company-wide perspective, Windows Blue is part of a broader effort to advance our devices and services for Microsoft," Reller said.

The software maker has sold about 100 million Windows 8 licenses since the OS was launched in October 2013.

Microsoft had worked to completely overhaul its flagship OS to make it more interesting to users in the midst of a transfer to mobile, touch-based computing.

According to research firm IDC, Windows 8 had been unsuccessful to reverse the falling PC market that witnessed record shipment slump during the latest quarter of 2013.