Windows 10 Feature Focus: CompactOS
 

Microsoft took a serious look at how to save space from the operating system files with Windows 8.1 Update. What they came up with at the time was WIMBoot, which used the recovery partition’s compressed WIM image file as the basis for most of the system files needed by Windows. Since the recovery partition is at least 4 GB in size, this is a pretty substantial savings especially on the lower cost devices which WIMBoot was targeted at.

I’ve discussed the changes with Windows 10 a couple of times, but a recent blog post from Michael Niehaus outlines how the new system works, what it is called, and how to manually enable it.

The last bit there is pretty important, since moving to WIMBoot was not something that could be done easily. It had to be done at the time the system image was put onto the computer, and there were a couple of extra steps OEMs could take in order to incorporate their own software into the WIMBoot.

http://www.anandtech.com/show/9676/w...ocus-compactos