Usually this occurs if another device was using E:\ when the drive was connected.

However, you can change the drive letter back, provided E:\ is not currently used by another device. Windows Explorer will show you what's in use.

In Control Panel, type the word Disk and select Create and Format Disk Partitions.
Follow the steps below:

Attached Files (Click to download or enlarge) (Only available when you are logged in)
2018-01-18_11-35-54.jpg (89.96 KB, 44 downloads)
2018-01-18_11-38-27.jpg (223.77 KB, 44 downloads)

BIAB & RB2026 Win.(Audiophile), Windows 10 Professional & Windows 11, Sonar Platinum, Cakewalk by Bandlab, Izotope Prod.Bundle, Roland RD-1000, Synthogy Ivory, Kontakt, Focusrite 18i20, KetronSD2, NS40M Monitors, Pioneer Active Monitors