dynamic mode allows you to take, say, 2 individual drives and say for example you had one drive E: with 3 GB left on it, you can put it into dynamic mode and span that to drive D: increasing drive D: by 3GB. However, I THINK that may not be possible on the primary partition. I'll have to look into it. Anyhow, what I was saying is that depending on size, he converted to NTFS, has a FAT32 second drive, updated to XP(if I remember right, have to reread this post) and now it doesn't recognize it. Could be because of the size of the drive and the FAT32 limitations in XP for FAT32 partitions which was corrected in SP1 but again, I'm not sure if this applies to a secondary drive or not. Have to research it.