The Reserved Storage feature introduced with version 1903 of Windows 10 makes sure that there is always a sufficient amount of free space for updates, apps, and system caches.
With default settings, Windows 10 sets aside about 7 GB for Reserved Storage, but it will vary over time based on how you use Windows 10.
There are two factors that influence the size of Reserved Storage. One is optional features. The other is, installed languages.
Optional features are the features that might have been acquired by Windows or manually installed by you. If you are not using any of the installed optional features, you can uninstall them to reduce the space set aside for Reserved Storage. For instance, the Windows Hello Face is one of the optional features automatically acquired by Windows 10, but it’s not useful unless you are using facial recognition to sign in to Windows 10.
Similarly, language packs also increase the Reserved Storage space as enough space is required to maintain these language packs when updates are installed. If you have installed two or more languages but don’t use all of them, you can uninstall them.
Now that you know what increases the Reserved Storage, you can uninstall unwanted optional features and languages that you don’t use. Here is how.
Uninstall optional features
Step 1: Open the Settings app by opening the Start menu and then clicking on the gear/settings icon.
Step 2: Navigate to Apps > Apps & features. Click on the Manage optional features link.
Step 3: Here, you can see all installed optional features on your PC. To uninstall an item, click on it and then click the Uninstall button.
Uninstall installed languages
Step 1: Open the Settings app. Navigate to Time & Language > Language.
Step 2: Select a language that you want to uninstall and then click on the Remove button to uninstall the language pack.