This simple chart from Microsoft shows what version of Windows 10 you can get if you decide to take Microsoft up on its offer for a free upgrade from Windows 7 or Windows 8.
The free upgrade only lasts a year, and you'll need a registered version of Windows 7 or 8 to take advantage of the offer. Microsoft also says that Windows 10 Home will make Windows updates completely automatic for users.
You can check which version of Windows 10 you'll be eligible below.
Microsoft
Earlier today, Microsoft announced a July 29 launch date for Windows 10, and you can reserve your copy of Windows 10 by opening up the new "Get Windows 10" app that resides in your Windows toolbar.