That only shows one disk attached, a 500GB that is your system drive. Is the external plugged in?

Sorry:

kcoutriers@kcoutriers-Mecer-X102 ~ $ sudo fdisk -l

Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000df24c

Device Boot Start End Blocks Id System
/dev/sda1 * 2048 960088063 480043008 83 Linux
/dev/sda2 960090110 976771071 8340481 5 Extended
/dev/sda5 960090112 976771071 8340480 82 Linux swap / Solaris

Disk /dev/sdb: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000ab78a

Device Boot Start End Blocks Id System
/dev/sdb1 * 2048 3907026943 1953512448 6 FAT16
/dev/sdb2 3907028992 3907029167 88 6 FAT16

kcoutriers@kcoutriers-Mecer-X102 ~ $ sudo fdisk -l

Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000df24c

Device Boot Start End Blocks Id System
/dev/sda1 * 2048 960088063 480043008 83 Linux
/dev/sda2 960090110 976771071 8340481 5 Extended
/dev/sda5 960090112 976771071 8340480 82 Linux swap / Solaris

Disk /dev/sdb: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000ab78a

Device Boot Start End Blocks Id System
/dev/sdb1 * 2048 3907026943 1953512448 6 FAT16
/dev/sdb2 3907028992 3907029167 88 6 FAT16

Hello???

linux does not care about the partition ID and it is independent of the actual file system type. In addition linux would not automatically change it even if the partition was reformatted.

Post the output of the command:
sudo file -s /dev/sdb1

Your fdisk output in post 17 clearly shows the second drive with two partitions. When you change the "Type" of a partition, you should get a pop up indicating this will delete all data on that partition. That's the way it works on the systems I use, I don't use Mint so maybe??

You can't edit mount options as a normal user, you need root/administrator privileges. You could open a terminal and use sudo:

sudo filemanager (replace filemanager with whatever the name of the file manager is on whichever version of Mint you are using)

That should allow you to access your partitions.

I am not at home at present but will post the command sudo file -s /dev/sdb1 later on.

@ yancek, when i changed the partition "Type" nothing popped up??? No pop ups whatsoever! That is why I'm certain that the Hdd was not formatted. IS sudo Filemanager something that I must download???

No. What I am trying to explain is that you need root/administrator privileges to make changes outside your /home/user directory in almost all cases. You are trying to change mount option and that needs to be done as root/administrator, in Mint that means you use sudo. filemanager was an example as I explained. I don't know what file manager your Mint version uses so you will have to find that out for yourself. As for the pop up, maybe you won't see it, the Linux distribution I am using does that and maybe Mint does not.

As pointed out earlier, changing the "Type" of partition requires formatting.
If the partitions on the 2TB drive show up in the fdisk output, they should be available for you to use but in all likelihood the owner:group will be root. Check under the /media/username directory I suggested earlier for the UUID.

You apparently have two partitions on your external drive, sdb1 and sdb2. Neither of them are mounted, but you can attempt to mount them by hand. My guess is you simply don't have the NTFS drivers installed which is why they aren't auto-mounting, but the output of the mount command will let us know for sure:
Post any and all output from these commands.

Please see below:

kcoutriers@kcoutriers-Mecer-X102 ~ $ sudo mkdir /mnt/usb1 /mnt/usb2
[sudo] password for kcoutriers:
kcoutriers@kcoutriers-Mecer-X102 ~ $ sudo mkdir /mnt/usb1 /mnt/usb2
mkdir: cannot create directory /mnt/usb1: File exists
mkdir: cannot create directory /mnt/usb2: File exists
kcoutriers@kcoutriers-Mecer-X102 ~ $ sudo mount /dev/sdb1 /mnt/usb1
mount: you must specify the filesystem type
kcoutriers@kcoutriers-Mecer-X102 ~ $ sudo mount /dev/sdb2 /mnt/usb2
mount: you must specify the filesystem type
kcoutriers@kcoutriers-Mecer-X102 ~ $ sudo mount /dev/sdb2 /mnt/usb2
mount: you must specify the filesystem type
kcoutriers@kcoutriers-Mecer-X102 ~ $ df -h
Filesystem Size Used Avail Use Mounted on
/dev/sda1 451G 10G 418G 3% /
none 4,0K 0 4,0K 0% /sys/fs/cgroup
udev 5,9G 4,0K 5,9G 1% /dev
tmpfs 1,2G 1,4M 1,2G 1% /run
none 5,0M 0 5,0M 0% /run/lock
none 5,9G 1008K 5,9G 1% /run/shm
none 100M 24K 100M 1% /run/user
kcoutriers@kcoutriers-Mecer-X102 ~ $ mount
/dev/sda1 on / type ext4 (rw,errors=remount-ro)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
none on /sys/fs/cgroup type tmpfs (rw)
none on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755)
none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880)
none on /run/shm type tmpfs (rw,nosuid,nodev)
none on /run/user type tmpfs (rw,noexec,nosuid,nodev,size=104857600,mode=0755)
none on /sys/fs/pstore type pstore (rw)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev)
systemd on /sys/fs/cgroup/systemd type cgroup (rw,noexec,nosuid,nodev,none,name=systemd)
gvfsd-fuse on /run/user/1000/gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,user=kcoutriers)

So it wasn't able to auto-detect the filesystem type, that's interesting. What if you add "-t ntfs" to the mount command:
If it says ntfs is an unrecognized filesystem type, then you need to open up your software manager and search for ntfs and install it. The name of the package should be something like "ntfs-utils" or "ntfs-3g" or something like that.

You did not post the output of the command:
sudo file -s /dev/sdb1

Sorry:

kcoutriers@kcoutriers-Mecer-X102 ~ $ sudo file -s /dev/sdb1
[sudo] password for kcoutriers:
/dev/sdb1: FoxPro FPT, blocks size 0, next free block index 1124103168

kcoutriers@kcoutriers-Mecer-X102 ~ $ sudo mount -t ntfs /dev/sdb1 /mnt/usb1
NTFS signature is missing.
Failed to mount '/dev/sdb1': Invalid argument
The device '/dev/sdb1' doesn't seem to have a valid NTFS.
Maybe the wrong device is used? Or the whole disk instead of a
partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?
kcoutriers@kcoutriers-Mecer-X102 ~ $ sudo mount -t ntfs /dev/sdb2 /mnt/usb2
NTFS signature is missing.
Failed to mount '/dev/sdb2': Invalid argument
The device '/dev/sdb2' doesn't seem to have a valid NTFS.
Maybe the wrong device is used? Or the whole disk instead of a
partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?

Hm, well that's not good. I wonder if whatever you were doing with the partition type screwed up the filesystem. Did it ever prompt you for your password when you were playing with the partition types in that GUI?