In Jan – 2015, Microsoft will officially introduce Windows 10 Consumer Preview. If you have not installed Windows 10 Technical Preview yet, don’t be afraid of its error problems affecting your work, or you simply do not know when the official Windows 10 released, Microsoft will help you. Recently, Windows engineering team has released a simple tool to support users to update Windows 10 Technical Preview from Windows 7 or Windows 8.1 through the Windows Update system in early 2015.
update-windows10-from-windows-7-8This is a useful tool for you to check and know exactly when Windows 10 Technical Preview has the latest version and in accordance with your current operating system.
However, you need to make sure that  your computer meets the minimum requirements of Windows 10:
  • * Processor: 1 gigahertz (GHz) or Faster
  • * RAM: 1 gigabyte (GB) (32-bit) or 2 GB (64-bit)
  • * Free hard disk space: 16 GB
  • * Graphics card: Microsoft DirectX 9 graphics device with WDDM driver
  • * A Microsoft account and Internet access

See  more details about Windows 10

After determining your device can install Windows 10 or not, all you need is just check with that tool and wait until having the latest update.
After you install this tool, you will receive a message with the content “Windows Update Will let you know khi Latest preview build is ready to install on this PC in early 2015.”
Also, if you can not wait until next year, you can also download the Windows 10 techical through the official download page here. To be sure, you should install Windows 10 with virtual software like VMWare or VirtualBox to avoid affecting your currently operating system.
Information for those who doubt about this tool: This is a tool to be released officially by Microsoft of Insider Program. It checks and allows you to upgrade from Windows 7 or 8.1 to Windows 10 Technical Preview through Windows Update .

Link download (choose the link dedicated to the operating system you are using)