Windows updates require a lot of disk space. This is a problem with low internal memory devices. Microsoft fixes this by "reserving" some disk space for updates in the next release of Windows 10, codenamed 19H1.
Microsoft has been pushing for years on cheap laptops with small hard drives. Anyone who has ever used one has quickly encountered a major problem: there is usually not enough disk space to install critical updates. This eliminates the need for important patches, security updates, and new features. Although you should not update to the latest version of Windows on the first day, you would ultimately like to get there. So that's a serious problem.
At present it is possible to delete as many files and programs as possible or to load the update into an external memory. No answer is always easy, especially for students who have a cheap device, no USB drive and the need to keep all their files and programs.
Microsoft is trying to do this with a method that will be undisputed. From the next major version (and now also available for insiders) reserves Microsoft at least 7 gigabytes of space on your hard drive.
The space is not completely wasted. Windows will save temporary files here if no disk space is needed for updates. Files created by apps and processes that would take up space are now included in this reserved space. If an update is to be performed, Windows automatically deletes all files in the reserved memory and uses the space for downloading update files.
Microsoft states that this does not happen through a virtual disk. As Microsoft's Craig Barkhouse explains in the TechNet comments:
Instead, we developed an elegant solution that adds new support to NTFS. The idea is that NTFS provides a mechanism for the maintenance stack to indicate how much space has to be reserved, for example 7 GB. Then NTFS will reserve this 7GB for maintenance purposes only. What does that do? Well, the visible free space on C: drops by 7 GB, which reduces the space requirements of normal applications. However, maintenance can use these 7 GB.
How much space is allocated depends on the optional features and languages that you have installed. The more features and languages are available on the system, the more space is reserved for these functions to be properly updated. If you later uninstall a feature or language, the space reserved will be reduced.
Microsoft says reserved memory should start at about 7 gigabytes and go up from there. nothing to lose. However, some users have less than 7 gigabytes of temporary files at the same time. These users see less storage space overall. It's a compromise that will help some people while reducing available storage for others.
about Mary Jo Foley / ZDNet