Hello, all. I have a couple thumb drives that I need to work with both an older Macbook Pro (circa 2009 Intel Core 2 Duo 2.4 GHz running OS 10.6.8) and PC. I don't have admin privileges on the PC so can't format on that machine. I know that I need to format to FAT but when I use the Erase function on Disk Utility (setting the format to MS-DOS (FAT)), it erases the drive but then reverts back to Mac OS Extended (Journaled). In other words, the formatting doesn't seem to 'stick'. I am making sure to select the top (master) sidebar entry for the drive, not the indented one (hope that makes sense). On one of the drives I created a partition that was FAT and that seemed to work fine on the PC but this other drive is being suborn. I've searched the archives but can't find this specific problem solved. Any help appreciated. ---------- I've also tried erasing with a zero data pass. No dice.