Low Disk Space Warning for OEM Partition

slcjra said:

I have this same problem.  Anyone have an answer?

Yes, here's the answer. First, it's useful to understand that the April 2018 update for some users caused a partition which should normally remain hidden to become visible, and Windows automatically assigned it a drive letter. This partition, which is nearly full, then provokes Windows to repeatedly warn you of low disk space.

The solution is to remove the drive letter assigned to that partition. This will make it invisible again (as it should be), and the low disk space warnings will cease.

This solution was provided by Tiero Chi, a Microsoft agent. Here are the steps. Follow them carefully:

Microsoft is aware that previously-hidden partitions are improperly being assigned drive letters after installing the April 2018 Update.  As a result, they now appear in Disk Management and File Explorer.  These partitions are typically recovery partitions used by the Windows Recovery Environment or by the Original Equipment Manufacturer.  It is not recommended that you attempt to delete or reformat these partitions as this may have adverse effects on your ability to recover Windows.  Microsoft is currently working to address the issue in a future Windows Update, and we’ll update this thread when a solution becomes available. 

(Update 5/14/18:  The solution that will soon be released via Windows Update will only prevent this issue from occurring for devices that install the April 2018 Updateafter the solution is released.  If you've already installed the April 2018 Update and are experiencing this issue, you'll need to follow the steps below if you want to hide these partitions.)

Although you can safely ignore these partitions, if you prefer do away with the low disk space warnings and hide the partitions so they no longer appear in File Explorer, you can do so by manually removing the partition’s assigned drive letter.  To do this:

1. Select the Start button, type cmd and then right-click Command Prompt in the search results and select Run as administrator.

2. In the Administrator:  Command Prompt window, type diskpart and press Enter. 

3. Type list volume and press Enter.

4. Make note of the volume number for the drive letter you want to remove.  For example, if the drive letter you want to remove is Drive “G”, note the volume number for Drive G. 

5. Type the following command, and press Enter. 

 select volume <volume number>

When typing this command, in place of <volume number>, substitute the volume number you made note of in Step 4.   In the example above, if the volume number for drive G is 5, you would type: select volume 5

6. Type the following command and press Enter.

remove letter=<drive letter>

When typing this command, in place of <drive letter>, substitute the drive letter you want to remove.  In this example, you would type: remove letter=G

7. Close the Command Prompt window.se. I did these steps and can confirm that it works.