After a long wait, Microsoft started pushing out its latest Windows OS, Windows 10, to eligible devices around the world. Starting Wednesday, 29 July, Windows-supported devices will be treated with a free or paid upgrade depending on the eligibility criteria laid out by the software giant.

The latest version of Windows brings a host of new features and delivers a refreshing user experience. Microsoft Windows 10 is being rolled out in 190 countries in a phased manner. Users will receive an upgrade notification when the new OS is ready to be installed.

The official rollout of Windows 10 has garnered positive response so far with users and publications applauding the new OS. Microsoft's decision to offer Windows 10 as a free upgrade to those running genuine predecessors has encouraged several users to jump on the bandwagon.

This is the first time a new version of Windows OS is being offered as a free upgrade. However, Apple fans are all too familiar with free OS X upgrades.

Windows 10 is being offered for free only to those who are running the genuine versions of Windows 7 and Windows 8 operating systems for the first year. If users miss the free upgrade offer in the first year, they will be asked to shell out the usual license fee, $120 for Home and $200 for the Professional version.

Windows 10 brings several irresistible features, making it a worthy upgrade. The new OS welcomes back the Start Menu, loss of which had angered many Windows 8 users. It also offer Cortana integration, Action Center, DirectX 12 support for gaming, all-new Microsoft Edge browser and a unified platform for all devices including mobile, tablets, Raspberry Pi, Xbox and Hololens.

In India, Windows 10 will not get Cortana as the digital voice assistant will be limited to select countries including the United States, United Kingdom, China, France, Italy, Germany and Spain.

Upgrading to Windows 10 gives better security, thanks to the improved Windows Defender and Smart Screen that keeps virus, malware and phishing content at bay, Terry Myerson, executive vice president of Windows and Devices Group at Microsoft, said in the company's official blog.

With the help of Windows Hello, users get a personalised user experience and a fast, password-free login.