Mystery Virtual Disk

I've got a mystery virtual disk and I have no idea what it is, where it is or where it came from.

I can see it in Device Manager, I can see it in Intel SSD toolbox, but there's nothing in Disk Management. I've unhidden empty drives and files too.

JiminyBillyBob said:

I've got a mystery virtual disk and I have no idea what it is, where it is or where it came from....

That will most likely be Microsoft's Reserved Storage.

Microsoft said:

Through reserved storage, some disk space will be set aside to be used by updates, apps, temporary files, and system caches. Microsoft's goal is to improve the day-to-day function of your PC by ensuring critical OS functions always have access to disk space. .... Reserved storage will be introduced automatically on devices that come with version 1903 pre-installed or those where 1903 was clean installed.

Enable or Disable Reserved Storage in Windows 10

Check Reserved Storage Size in Windows 10

hmmm...my reserved storage is over 9gb and I can't see that portable base layer in drive management

Are you using OneDrive's Personal Vault Option?

I remember testing driving that option with it's 3 file limit when it was first offered and it mysteriously created a virtual drive file here that's used with Bitlocker:

Farvatten said:

Are you using OneDrive's Personal Vault Option?

I remember testing driving that option with it's 3 file limit when it was first offered and it mysteriously created a virtual drive file here that's used with Bitlocker:

Haven't set it up on this installation, that folder is empty. No vhdx in there

JiminyBillyBob said:

Haven't set it up on this installation, that folder is empty. No vhdx in there

I'm hardly an expert on such things, but perhaps look for *.vhdx files or anything over 7 GB.

If it's any consolation I have 7 GB of Reserved Storage and it's not showing under Device Manager > Disk drives like the first image of your OP.

Farvatten said:

I'm hardly an expert on such things, but perhaps look for *.vhdx files or anything over 7 GB.

If it's any consolation I have 7 GB of Reserved Storage and it's not showing under Device Manager > Disk drives like the first image of your OP.

Might try that. good idea

Bastet said:

Do you have Windows Sandbox installed?
The Portable Base Layer/Virtual drive is the virtual drive for Sandbox use. I have this on Windows 10 pro.

I do, can you see it in Drive Management though?

Fabler2 said:

That's odd. I have Sandbox enabled and Portablebaselayer used to show in MiniTool but not showing now.

A change in 2004 maybe to hide it ? I'll try enabling it in my installation on my other partition and see if it shows up