If you find that the C or D Drive letter is missing from Explorer in Disk Management in Windows 11/10, maybe after an Update, try these solutions to resolve the issue.

How to get started with File Explorer tabs File Explorer tabs are already part of the File Explorer UI, provided that you’re running an up-to-date copy of Windows.

Why File Explorer Doesn't Show Folder Sizes Performance is the primary reason Microsoft has not included the functionality to display folder sizes in the Size column.