HP Compaq Series Hardware And Software Manual page 194

The list below describes the default sequence in which drive
numbers are assigned. (The actual startup sequence varies by
configuration.)
■
Default sequence for devices that boot as drive A:
1. Optical drive in an optional docking device (select models
only) or in an external MultiBay that contains a disc that
boots as drive A.
2. Optical drive in the internal MultiBay that contains a disc that
boots as drive A.
3. Diskette drive in an optional docking device (select models
only) or in an external MultiBay.
■
Default sequence for devices that boot as drive C:
1. An optical drive in an optional docking device (select models
only) or in an external MultiBay that contains a disc that
boots as drive C.
2. Optical drive in the internal MultiBay that contains a disc that
boots as drive C.
3. Hard drive in the notebook hard drive bay.
4. Hard drive in an optional docking device (select models only)
or in an external MultiBay.
✎
Since no drive letter is associated with the NIC, changing the boot
order of a NIC does not affect drive letters of the other devices.
Hardware and Software Guide
MultiBoot
8–3