Ejecting USB drives while in the Windows Recovery Console / System Recovery Command Prompt, so it is unlikely any of the utilities above will help. In such a situation, the following method using Diskpart should work:
diskpartand wait for the diskpart prompt (
- Note the volume number of the USB drive carefully (use listed properties such as drive letter, label, type and size for help)
select volume <number>, where
<number>is the volume number noted above
remove all dismount
exitto quit Diskpart
Now you should be able to safely remove your USB drive without fear of data loss.