OK, I have spent days reading about diskpart and label.exe and GPT drives and my head hurts.
A month ago my Windows Backups have started failing with an 0x8007007b error, an invalid filename, directory name or volume label is invalid. After checking the filenames and directory names and the length of run time of the backups I've determining the volume label of the Windows Recovery volume is missing. Why I don't know since it is normally a hidden partition. Maybe a Windows update made checking for the volume label a requirement, maybe a hard drive glitch.
So, not a problem, I'll just add a label to it. Well, not an easy task. Command prompt commands fail, Linux fails, diskpart fails. The problems appears to be tied to EFI and GPT disks. %$@#!
So, any suggestions how to add a volume label to a hidden, system, GPT drive, partition without reformatting it or the whole drive?? I've already considered removing it and smashing it with a hammer.
BTW The drive is in a 2 yr old Dell notebook.
I figured it out finally. GParted
Adding the volume label didn't resolve the Windows Backup problem!! %$@#^
The error was not due to the missing label or to files on the backup drive. There were corrupt files on the drive the data files were on!! A simple CHKDSK /F fixed the problem.
It would have been a WHOLE lot easier to resolve if Windows Backup issued the error when it encountered it rather than when it was done doing the backup. Then I would have had a clue as to where the problem existed.