Add method:

1. Right-click this computer and select Manage.

2. Find the disk management in management, check the mechanical hard disk, that is, the disk without C disk, and see if the capacity has changed. If there is no change, please repartition the disk.

3. Select a disk without a drive letter, select "Change drive letter and path", and then click the "Add" option in the pop-up window.

4. Then in the pop-up window, select E as its drive letter and click OK.

Step 5 restart it