Warning
Use an administrator account for these steps, and keep a recent backup before making repair or security changes.
What you will achieve
Get a USB disk visible again — or know when the problem is hardware not software.
1) Confirm hardware first
- Try another USB port and cable.
- Test on a second PC to rule out enclosure failure.
2) Assign drive letter in Disk Management
- Press Win + X, open Disk Management.
- If volume is healthy but letter missing, right-click → Change Drive Letter and Paths.
3) Repair filesystem if needed
chkdsk E: /f