Microsoft has officially announced about an event on January 21, where they are going to share details about an awesome build of Windows 10 – could be Consumer Preview-, in the meantime, the software giant has made available a tool on their website which readies Windows 7 or Windows 8.1 PCs to grab Windows 10 Preview in early 2015 via Windows Update.
Download Prepare this PC for Windows 10 Preview Tool from Microsoft
To get started, on Windows 7 or Windows 8.1, visit this page and click on ‘Prepare this PC now’ to download the tool to your computer.
First time, when you run it, Prepare this PC dialog appears and says "Get your PC ready for the latest Windows Technical Preview from Window Update’.
When you click ‘OK’, the tool checks your system and shows the following dialog ‘your PC is now ready for Windows Technical Preview. Windows Update will let you know when the latest preview build is ready to install on this PC in early 2015’.
That’s it! Windows Update may update or notify you when Windows 10 Preview build is available to install on your PC.
You can also manually install the preview on another partition or a virtual machine by downloading the ISO file.