External HDD is not formatting from NTFS to exFAT

Delete the partition and start over.

 

I wasn't aware that you could format anything other than flash drives as exFAT. I thought I had tried once on a mechanical drive and it wasn't an option.

Also, just a FYI, if you format as exFAT on OS X, Windows isn't going to read it. But if you format as exFAT on Windows, OS X likes it just fine.

 

I have managed to change it to exfat now but still won't show on my MBP

 

If its a Western Digital I know some people have had issues with them on Macs until they've updated the firmware and or drivers (they have a TURBO driver). So its worth checking out their site to see if there is an update for your drive. Even if it isn't WD, its probably worth checking the manufacturer's site.

On side note, were you able to format as exFAT from Windows on a mechanical drive?

 

Btw: see the WiKi