LaCie P9233 error message 'Could not write file to destination (1,016)'

I am new to Mac and also the use of the external hard drive on them. Previously I have had a PC and just been able to drag and drop files and photos onto the hard disk drive as needed. When I attempt to drag and drop or even export a photo from my MacBook to my LaCie P9233 I get the following message 'Could not write file to destination (1,016)'. When I originally formatted the drive I split as I thought that would enable me to share it with a PC if I wanted to plug it into a PC at a friends house.

I have the following sections of the drive now:

Format: MS-DOS (FAT32)

Capacity: 79.68 GB

Format: Mac OS Extended (Journaled)

Capacity: 3.92 TB

It always me to drag and drop to the MS-DOS part of the drive but that is far too small for all my pictures.

How can I get it so I can just save images/file by either dragging and dropping or exporting? Please can anyone help?

Thanks