Microsoft confirms the Windows 10 release date to be 29 July 2015.
Windows 7 and 8 users would have seen a small Windows icon appear in the System Tray (bottom right corner of the taskbar near the clock). Clicking on the icon allows you to reserve your copy of Windows 10 when it is released. You will receive a download link on 29 July. Remember, it is a 3 Gb+ download, so run it overnight.
If you’re not using Windows 7 or 8.1 then you won’t qualify for the free upgrade. Windows XP is unsupported by Microsoft and I don’t think Vista has much of a life-cycle left either.
I will be posting some more info on Windows 10 regularly leading up to the release date, so stay tuned.