In a couple of weeks, Windows May 2020 Update will begin rolling out to consumers and enterprises and it will arrive with the ability to manage Reserved Storage from the command line.

Reserved Storage was introduced with May 2019 update and it's a "feature" that sets aside a portion of the Windows system drive to be used for critical system and driver updates.

This reserved storage, though, starts at a minimum of 7GB and can increase in size as needed for existing Windows 10 computers. For OEMs and new PCs, Microsoft has stated that 32GB of reserved storage will be required.

Microsoft said Reserved Storage addresses storage shortage problemswhen performing updates by reserving a certain amount of space for apps, updates, and drivers that are needed Windows to function smoothly.

To see the current reserved storage settings, in the May 2019 Update and later, look in Settings > System > Storage and then click on the "Show more categories" link. 

You will then be shown a System & reserved category to see more detailed information on how much space the system files and Reserved storage is using, as seen below.

Reserved Storage

For those who do not want to use the Reserved storage feature, users were disabling it via the Registry, which is a risky process.

With May 2020 Update, Microsoft is finally introducing options to tweak Reserved Storage via the DISM command-line tool.

Managing Reserved storage from the command line

For those who wish to manage reserved storage, you will be able to use the DISM command.

DISM, or Deployment Image Servicing and Management tool, is a command-line tool used to "service and prepare Windows images, including those used for Windows PE, Windows Recovery Environment (Windows RE) and Windows Setup."

Starting with Windows 10 2004, or the May 2020 update, Microsoft has added additional commands to DISM that allow managed Windows 10 Reserved storage.

To use DISM, you first need to launch a Windows 10 elevated command prompt. You can then use one of the following commands to manage Reserved storage.

Starting with Windows 10 2004, or the May 2020 update, Microsoft has added additional commands to DISM that allow managed Windows 10 Reserved storage.

To use DISM, you first need to launch a Windows 10 elevated command prompt. You can then use one of the following commands to manage Reserved storage.

To check whether Reserved storage is enabled:

DISM /Online /Get-ReservedStorageState

To enable reserved storage, you can run the following command:

DISM /Online /Set-ReservedStorageState /State:Enabled

To disable reserved storage, you can run the following command:

Dism /Online /Set-ReservedStorageState /State:Disabled

Windows 10 May 2020 Update (version 2004) is scheduled to begin rolling out next month. If you're an Insider in Release Preview ring, you can download and install the feature update today.

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