When you create a Shadow PC, the additional storage first appears as "Offline" and is therefore not accessible from the file manager.

Here is the procedure to follow:

1. Click the magnifying glass at the bottom of your screen.
   
   

2. Search for "Create and format hard disk partitions" and click on the suggestion of the same name. A window opens showing the 2 disks on your Shadow.
   At the bottom of this window are illustrated the two disks that make up your storage. Do not touch disk 0 where Windows is located
   
   
   

3. Right-click on disk 1 at the bottom and click on "Online" to activate it.
   
   
   

4. You can close this window and this disk will appear in your file manager.