mounting external HDD 2

Sometimes the external hard disk drive won't mount. Maybe this is the problem:

The stupid thing you won't get a response or fault message using Storage Device Manager.
Using : sudo mount -a you will get:

Mount is denied because NTFS is marked to be in use. Choose one action:

Choice 1: If you have Windows then disconnect the external devices by
clicking on the 'Safely Remove Hardware' icon in the Windows
taskbar then shutdown Windows cleanly.

Choice 2: If you don't have Windows then you can use the 'force' option for
your own responsibility. For example type on the command line:

mount -t ntfs-3g /dev/sdb1 /media/sdb1 -o force
Trying this the HDDF is indeed mounted