Livemint.com: Windows 10: Everything you must know
Microsoft’s next PC operating system is available from 29 July. Windows 8 (and Windows 8.1) will no longer be the default operating system that comes with new PCs, and anyone who is currently making do with Windows 8 can look forward to upgrading to an OS which is better in every way—Windows 10. Windows 10 offers faster start-up and performance, start menu, universal apps, action centre and Microsoft Edge browser. If your PC is currently running Windows 7 (32-bit or 64-bit) or Windows 8.1 (32-bit or 64-bit), you are eligible for the Windows 10 upgrade.