Have you ever wanted to mount your external drive, but your linux box refused it? Most likely it was caused by you forgot to unplug / disconnect your external drive while you were in windows. Apparently, windows didn’t unplug / disconnect your external drive when it was turned off.
The logic way is restarting to your windows box, then unplug / disconnect your external drive. But it sucks. Why would we need to go to windows? The right way is using ntfsfix.
ntfsfix
So, if your external drive is in /dev/sdb1, it would be,
ntfsfix /dev/hdb1
