China DOS Union

People always say “the system boots from drive C by default.” Why (or how) does it default to booting from drive C? Is it because drive C is marked active, so the system defaults to booting from drive C? If what I mark active is not drive C but drive D, does that mean “the system boots from drive D by default”? Is the relevant command line written in the partition table? Thanks for the advice! Thanks!!

Under normal circumstances, drive C is not the same as drives D, E, and F. Although drive C is indeed set as the active partition, even so, drive C is still different from the other drives, because partitions have the concepts of a primary DOS partition and an extended DOS partition. The primary DOS partition is what we usually call drive C; and the extended DOS partition is divided again into logical DOS drives, namely drives D, E, and F.

To sum up, aside from the active partition parameter, there are still differences between drive C and the other drives, and that difference lies in the primary DOS partition and the extended DOS partition.