Finally Microsoft presented Windows 10 Preview version. You need to know that Windows 10 available for free for users that have an official Windows 7 or Windows 8.1. You can upgrade for free to Windows 10.
Till official release Microsoft has made available for download the Windows 10 Preview version, build 9926 buiwhich is available for free to download. Windows 10 9926 build ISO is available in over 20 languages. To download and install it you will have to choose which language version you want to download:
After downloading Windows 10 9925 build ISO, you will have to burn it on a USB Flash Drive. You can do it with a software like: ISO to USB
Installing Windows 10
To install Windows 10 you will have to make changes in BIOS to boot from USB in the BIOS/UEFI. n process of installation you will have to enter the Product Key to Activate the Windows.
The Product Key is: NKJFK-GPHP7-G8C3J-P6JXR-HQRJR
Windows 10 is not a complete version of Windows 10, and cannot be used from day to day. It is just a Demo version to let you know what it looks like.