Data Drive Bootcamp Permissions I have a Mac Pro 2012 running HS and Windows 8 on separate partitions on the same physical SSD.  It also has a data drive, a separate physical platter drive.  When I'm on the Mac side, all is well, but on the Windows side, I can only read from the data drive, I can't write to it. I'm not sure which side I have to change permissions on to change this? I don't want to mess anything up.
The external data drive is probably formatted Mac OS Extended (journaled), on which Windows can not write.
Choose a format that can be used by both OS for read and write, like MSDOS FAT or EXFAT.