It's NTFS not NTSC...

Just one letter but still.
Backup the date from the drive.
Right-click My Computer -> Manage
Click Disk Management in the left pane
Right click the disk on the bottom of the right pane -> Delete Volume
Right click again, Create Partition, Primary, assign half the storage
Right click again, Create Partition, Primary, rest of the storage.
Avoid secondary partitions (up to 4 primaries can be used).
Format each partition using a different file system.
That's it.
(Written from memory, may have to adjust).
Diogen.