Microsoft releases Windows 10 Technical Preview build 9879 ISO files and also makes the operating system available to the slow ring for the Windows Insider Program.

This is a good news for those users trying to clean install Windows 10 without having to install the first build and then upgrade. And now it’s also easier to build a dual-boot system using a VHD as you probably know upgrades are not possible using a virtual disk drive.

Furthermore, having available for download the ISO files, it also means that the Windows 10 build 9879 is also available in the slow ring for Windows Insiders. So if you still running build 9860, you can now go to the PC settings, Update and recovery, Preview builds, to install the latest version.

It’s also very important for you to know that clean install Windows 10 preview will require a product key; when you’re prompted, simply enter this product key: NKJFK-GPHP7-G8C3J-P6JXR-HQRJR

#WindowsInsiders 9879 is publishing to the Slow ring now.

— Gabriel Aul (@GabeAul) November 24, 2014

If you previously upgraded to the build 9879 from the fast ring, you can now change the settings in the Preview builds on PC settings to get the more stable version of Windows 10.

You can download all the ISO files for Windows 10 from this Microsoft page, and for those in United States, you can use the following links: 32-bit (x86), 64-bit (x64).