j0 all. I bought an external hard drive to my sister, filled it and sent it to her (she lives like 1200km from me), she gets it, can't use it. I start to dig, and finds out it uses GPT instead of MBR and that Windows XP (which she uses) can't read that. Annoyance. She sends it back (because none of the people she knows down there has 500GB spare backup space ) so I can set things straight. However, if you want to convert a disk to MBR the disk can't have any partitions. But the disk looks like (see below). What's that about? I know EFI is some Mac something (or intel something or something sumthin'). The Convert to MBR option is greyed out. Can I use another tool for that? What do I do? Thanks for looking! /Frick Disk2 is the external drive. It's a Seagate something.