Seagate with 2nd mac

[Faustina]

I copied photos from my mac laptop to new seagate and worked fine. Then trying to copy photos from my desktop mac and it is read only. I downloaded the Seagate dashboard and rebooted but still read only. I have 1 TB files (5TB storage) and I don't want to reformat and lose these files. Any ideas appreciated.

 

[popatim]

Assuming the drive is formatted as NTFS
http://www.seagate.com/support/downloads/item/ntfs-driver-for-mac-os-master-dl/