Drive list maintenace

Both past and present Drives are shown under ADVANCED/DRIVES.

It shows 2 D Drives one of which was shown as a backup.

Drive D is NOT a backup drive any more.

One might be an older disk the other  current ( I can't tell the differnce from this screen).

Drive D now contains Data and specifically redirected folders like My Documenta etc which are separately backed up.

 

How do I remove the old drive from the list without losing the data and add it back as the current D Drive??