Microsoft used smoke mirrors, colored filters and falling crystal dust to create the Windows 10 hero image for the desktop, but a YouTuber turned to his prowess with Adobe After Effects to recreate the magic.
While not identical, the background created by Khaos VFX is pretty similar to the one rolled out by Microsoft. If you're interested in downloading the image to use as the background on your Windows machine, head here. If you'd like to compare, here's the original version by Microsoft.
Also check out Microsoft's video showcasing the creation of the hero image for Windows 10:
Source: YouTube (Khaos VFX)