User's Manual

Section E.1:Hard Disk Basic Concepts 107
This is a typical partition layout for most newly purchased computers with a consumer version of
Microsoft Windows™ preinstalled.
E.1.3 Partitions within Partitions – An Overview of Extended
Partitions
Of course, over time it became obvious that four partitions would not be enough. As disk drives
continued to grow, it became more and more likely that a person could configure four reasonably-sized
partitions and still have disk space left over. There needed to be some way of creating more partitions.
Enter the extended partition. As you may have noticed in Table E–1, Partition Types, there is an
"Extended" partition type. It is this partition type that is at the heart of extended partitions.
When a partition is created and its type is set to "Extended," an extended partition table is created.
In essence, the extended partition is like a disk drive in its own right —— it has a partition table that
points to one or more partitions (now called logical partitions, as opposed to the four primary par-
titions) contained entirely within the extended partition itself. Figure E–7, Disk Drive With Extended
Partition shows a disk drive with one primary partition and one extended partition containing two log-
ical partitions (along with some unpartitioned free space).
Figure E–7 Disk Drive With Extended Partition