Microsoft is offering a free upgrade to Windows 10 for Windows 7, 8, and 8.1 users as well as smartphones and tablets running Windows OS in the first year. Also, Windows devices will get free updates for a lifetime to keep the system more secure. The upgrade will enhance the performance, security, add new features, and functionality to your existing system without any additional charges.
Step 1: To get an upgrade, visit http://windows.microsoft.com/en-in/windows-10/about and sign up with your email.
Step 2: Once you receive the approval, you will get an upgrade option in your Microsoft account from where you can download the Windows insider preview setup as shown in the screenshot.
Step 3: After downloading the Windows10InsiderPerview setup, run it as an administrator. Now, it will download about 2 GB updates. Click on "Install Update" button once the downloading is done.
Step 4: While installing updates, it will check the compatibility of your existing applications. If there is any app, which is not compatible with Windows 10, it will prompt you to uninstall that program.
Step 5: After you restart your PC, it will boot with core Windows installation process.
Step 6: Finally, you will see the first screen of the new Windows 10 as your desktop.
Step 7: Your entire data will be there in-place after up-gradation is done, but with some tweaks in the look. In case your not able to access the start button, right click on the taskbar and go to properties. Click on Start Menu tab and click on restore option. This shall resolve the issue.