Thanks, my issue is at the Windows end.
I formatted the drive for mac without encryption, moved to windows, downloaded this http://www.seagate.com/gb/en/suppor...lus-desk-mac/backup-plus-mac-software-master/ (made by Parallels) and works fine, windows can read it correctly.
If I do the same thing but formatting for mac with encryption windows cannot read it, it shows two volumes, one called OS X boot and another one with the name of the drive but unreadable.
I m trying to have an external drive that works on both Windows and Mac and requires password on both.