Windows 10 will launch July 29th for free for devices running Windows 7 and Windows 8.1, as well as new devices.
If you’re using a Windows 7 or Windows 8.1 machine, you should notice a Windows flag in your system tray. This is the “Get Windows 10” reservation launcher, which allows you to reserve Windows 10.
To do so, you simply need to click the “Reserve your free upgrade” button so Windows Update can be prepared to accept the update on launch date.
If you will be upgrading to Windows 10, here’s what version you will receive:
- Windows 7 Starter- Windows 10 Home
- Windows 7 Home Basic- Windows 10 Home
- Windows 7 Home Premium- Windows10 Home
- Windows 7 Professional– Windows 10 Pro
- Windows 7 Ultimate- Windows 10 Pro
- Windows 8.1- Windows 10 Home
- Windows 8.1 with Bing- Windows 10 Home
- Windows 8.1 Pro- Windows 10 Pro
- Windows Phone 8.1- Windows 10 Mobile
To upgrade, you will need to have Windows 7 with Service Pack 1 or Windows 8.1 with Update 2.
Source: Windows Blog