Microsoft has announced an important change regarding Windows 10 and reserved storage yesterday. Starting with the next Windows 10 update, which Microsoft explicitly named “1903” in the blog post (this is a first, to our knowledge), the desktop OS will now reserve disk space for OS updates, apps, temporary files, and caches. For the most part, this is about helping users to install system updates without having first to free up space on their PCs.
“Reserved storage will be introduced automatically on devices that come with version 1903 pre-installed or those where 1903 was clean installed,” wrote Jesse Rajwan, Program Manager at Microsoft. When reserved storage is enabled, it should take around 7GB of disk space, though Microsoft noted that the amount of storage will vary over time depending on optional features and installed languages that users choose.
I have supported a number of clients (one just this week) who have bought low cost "laptops" (such as this one - honestly DO NOT BUY ONE!) - which come with only 32Gb of onboard storage. Essentially, these devices have run out of storage - before you have even taken them out of the box! Then Microsoft want to take another ~7Gb. It's not gonna happen!