This is the newest version of Windows. If you expected that Windows 9 will be releases than you were wrong, cause is TEN. Before you download the free version of win10 you must check the system requirements.
Processor: 1 GHz+
RAM’s: minimum 1 GB for 32bit version or 2GB for 64bit.
Free HDD space: 16 GB.
Download Windows 10 Technical Preview from Microsoft.com here (Size: 3.92 GB).