It's becoming increasingly common to store Windows 10 on a 120 GB SSD, but that comes with some issues. Namely, after the pagefile, temporary files, drivers, programs, and documents, you aren't left with a whole lot of space.
For some, the concern is that they won't be able to fit a game on their tiny drive, but Microsoft has other issues. The company is looking to reduce the instances where a Windows update fails due to lack of space.
In its latest Insider build, Windows 10 1903 reserves an additional 7.02 GB of space to “ensure proper performance and successful updates”. This is on top of the 5.50 GB from the OS and is not really supposed to be tampered with.
Moving Temp Files
However, though that 7 GB of space is technically gone, Microsoft says most users won't see a huge difference in space. That's because temporary files, the system cache, and more will be placed in that reserved storage instead.
When it comes time to update, the plan is to assumedly to make room by removing temporary files that won't be needed. It's also worth noting that this change won't be applied to your PC if you're just updating via the normal channels. It's only if you do a clean install of 1809 or get a device with it pre-installed you'll notice the difference.
This is clearly a move by Microsoft to try and increase the reliability of its updates. It's come under fire recently for releasing builds with document deleting bugs, blue screens, zipping issues, and audio bugs. Removing the opportunity for user error will help a little, but it's clear changes also need to happen internally.