On Windows 10 (OS Build 18298) (19H1) you can now find a new feature called Reserved Storage. If you have recently upgraded to OS Build 18298 then this feature will by default be disabled. Below I will show you how to enable it but firstly what is Reserved Storage?

Well it is what it is “Reserved Storage”. Microsoft decided that it would be a brilliant idea to take a chunk of your available disk space and use it to store important files such as Windows Updates and System Files. This is to help combat the number of feature update failures which occur due to low disk space. So the plan is to reserve 7-8GB of disk space and set it aside for when Windows Updates may need it.

According to Microsoft the size of the reserved space could increase depending on usage.

After upgrading to OS Build 18323.1000 I noticed that I had a new drive called PortableBaseLayer which was 7.5GB-7.99GB in size. See below:

What I found that was unusual was the fact that this drive did not appear prior to upgrading to OS Build 18323 and after doing some digging I found that the Reserved Storage feature was disabled, so why was this showing? So even if the feature is disabled Windows will still take the portion of storage space for no reason.

As you can see from the images above the drive is a Microsoft Virtual Disk with a size of 8.00GB and is NTFS set to Read Only. After not knowing what it was I just right clicked the drive and ejected it like standard removable media but It did not vanish, until I restarted the device.

As mentioned above if you have upgraded from a previous build then this feature will be disabled. As far as I know it is only enabled bedefault if you install a fresh copy of the OS Build. So to enable this feature we will jump in to the registry.

Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\ReserveManager and find the following DWORD called ShippedWithReserves and double click to edit the value from 0 to 1. If it is already set to 1 then this Reserved Storage is already enabled.

Below set the Value data to 1 and press OK.

Once Reserved Storage is enabled then navigate to
Settings / System / Storage / Show More Categories / System & Reserved and you can see a detailed breakdown of the data being stored in the Reserved Storage.

Although it seems like a good idea on Microsoft’s behalf a lot of people will not be best pleased that 8GB or so of storage space will be set aside for Windows Updates and other uses. And even if the user disables the feature the space is still being reserved.