When an optional feature is installed, Windows will increase the amount of reserved storage to ensure there is space to maintain this feature on your device when updates are installed.
These may be pre-installed, acquired on demand by the system, or installed manually by you. Many optional features are available for Windows. Also, the following two factors influence how reserved storage changes size on your device:
Microsoft may adjust the size of reserved storage in the future based on diagnostic data or feedback. For example, temporary files that consume general free space today on your device may consume space from reserved storage in the future. The reserved storage size will start at about 7GB, however the amount of reserved space will vary over time based on how you use your device.
