1. Use DiskPart Utility
Go to command line and type diskpart.
Type this command to list all disks in computer:
list disk
If you want to check info about a disk (for example, disk 1), type these commands:
select disk 1
detail disk
2. Run Disk Management Utility
Go to Start and type “Disk Management”. An option to open Disk Manager will appear.
Alternatively, type Windows + R and enter “diskmgmt.msc”
Each row corresponds to a different disk, as seen on diskpart utility.
Remember that you cannot merge partitions from different disks.
External references
https://support.purestorage.com/Solutions/Microsoft_Platform_Guide/Multipath-IO_and_Storage_Settings/View_Disk_Properties_and_LUN_Information_in_Windows
https://softwarekeep.com/help-center/how-to-merge-partitions-in-windows-10