In File Explorer within Windows 10, your local drives twice in the Navigation Pane. Once under Desktop, and once Under This PC …
You can fix this by removing the following keys from the Windows Registry:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Desktop\NameSpace\DelegateFolders\{F5FB2C77-0E2F-4A16-A381-3E560C68BC83}
HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Explorer\Desktop\NameSpace\DelegateFolders\{F5FB2C77-0E2F-4A16-A381-3E560C68BC83}
As a result, the drives under Desktop are removed …
If you removed this registry key, but it it re-appeared, then Windows Update KB3097617 is probably to blame. This update restores some default Registry Keys for Windows Explorer. Just run the steps again, and you should be fine.