I have four internal drives and an external Drobo drive. The internal drives are my concern in this query. All are working well and I could just leave well alone, but my sense of order requires me to get all these different descriptions into conformity with each other. Active/Not Active; Logical Drive/Primary Partition; Disk number vs. letter order? Can someone please give me a step-by-step way to get this all straight? For a start, the designation "Disk 0" always confuses me as there is no SATA slot on the motherboard for that. What is the correlation between motherboard SATA slot numbers and the disk numbers in the Disk Management table? Left-click on image to see the table.