I am trying to figure out how to partition my HD so that it can speak easily between a Windows formatted HD and Mac HD's without the Error Code -0 (meaning it won't transfer files larger than 4gb's from HD to HD. I use a Mac running Snow Leopard and I am formatting using Disk Utility. I have always done the MS-DOS (FAT) format but like I said I am getting the Error Code -0 and it's become more of a nuinsance than anything. My options are Mac OS Extended (Journaled), Mac OS Extended, Mac OS Extended (Case-Sensitive, Journaled), Mac OS Extended (Case-Sensitive), MS-DOS (FAT) and Free Space. Is it possible to get the best option explained to me in a way that's more understandable than from the research I have discovered. Also I know Finder has issues thus the reasoning for the 4gb limit. I have downloaded a 3rd party app Path Finder to allow me to bypass that limit except whenever I copy from one HD to another it disappears once the transfer is complete. Thanks again for all the help.