I have three SCSI hard drives on my computer. Their file systems are all NTFS. Drives C: and D: have 8.47 GB capacities. Drive F: has a 68.45 GB capacity. Drive E: is an IDE CD writer. Drives C: and D: are visible if I try to make backup images of them, but drive F: is not. Asside from the capacity difference, the only other significant difference of which I am aware is that drives C: and D: are basic primary partitions but drive F: is a dynamic simple volume as displayed by the disk manager. I thought that the drive letter gap might be significant, so I used the disk manager to swap the letters for drives E: and F:. That didn't make any difference, so I swapped them back. Any ideas?