hard disk won't autodetect in the BIOS setup program
The hard disk drive cannot be detected using the autodetect utility
within the BIOS setup program. Usually, the BIOS will pause for
a long time while it searches for the drive, and then will return
saying that the drive was not found.
Diagnosis: There are many, many different reasons why a hard disk
may not be visible to the BIOS setup program. They usually fall
into two major categories: problems with configuration (how the
drives are set up) and problems with the drive itself. There are
occasionally problems with the hard disk controller, but these are
If this is a new hard disk, or a hard disk moved into a new system,
or the system was just built or upgraded, I'd recommend reading
this section that discusses common problems when setting up or working
on new systems.
If you have another system that you can try the drive in, it is
a good idea to connect it to the other PC and see if it will be
detected there. Bear in mind that moving the disk to a new PC can
introduce other variables that might confuse the issue, but I have
seen this be a very effective way to isolate the trouble to either
the hard disk or the PC. Similarly, if you try another identical
(or even just similar) disk in place of the one not working, that
can tell you if the problem is the drive or the hard disk controller
(of course, the drive could just be jumpered incorrectly; see below
for more). If the hard disk controller is implicated, troubleshoot
You should determine if the hard disk has power and is spinning
up. The only reliable way to do this is to take the cover off the
PC and listen as you turn the power on. You should be able to hear
the hard disk spin up. If it spins up and then spins back down again
immediately, this is a sign of a problem with the disk itself. If
it doesn't spin up at all, then either the drive is dead, or there
is a problem with the power connection to the drive. Make sure the
power input connection to the disk is tight. Try swapping it with
a different power connector and see if the drive comes up. If other
peripherals don't have power either this could be a power supply
problem. Sometimes hard disks will not spin up if there isn't sufficient
power at startup. This can happen especially with older power supplies.
If the disk is SCSI, you need to check all of the various parts
of the SCSI chain. The SCSI host adapter (controller) must be checked
to ensure that it is working properly. The hard disk and all other
devices on the SCSI chain must have a different device ID. The termination
must be set up correctly. See here for more details on SCSI configuration.
If the disk is on an IDE channel with another drive (hard disk or
CD-ROM), then you should try the disk by itself on the channel.
You may need to change the jumpers on the drive to do this, but
you definitely need to try the drive without the complicating factor
of another device on the channel. If the disk works by itself but
not when set up with another drive, you may have a master/slave
conflict. (Note that sometimes there actually is no conflict; the
drive may not have been jumpered correctly, and you may have inadvertently
fixed this when the configuration was changed).
Make sure that the hard disk is configured properly. The jumpers
should be set correctly. The ribbon cable should be inserted properly
and pin 1 on the drive should be matched up with pin 1 on the hard
disk controller or motherboard.
If you had a master and a slave drive on the IDE channel and removed
one of the two drives, the one that remains may need to be rejumpered.
Some hard disks--for example those manufactured by Western Digital--use
different jumpers for when they are a master with a slave drive
present vs. when they are alone on a channel. If you leave a WD
drive jumpered as master when it is alone on the channel, it may
not boot, or may boot only after a long delay. Other manufacturers'
drives may work just fine this way, however.
Make sure that if you are using only one controller, that the ribbon
cable for the drive is connected to the correct IDE port on the
motherboard or controller. If you connect it to the secondary channel's
port instead of the primary channel's, then the disk may not be
Make sure that the IDE controller is enabled; on modern systems
the IDE controllers are enabled or disabled using BIOS settings.
It is common for the secondary controller to be disabled; if you
are adding a hard disk to the secondary channel you will need to
enable the channel. The primary IDE channel should of course also
be enabled if the primary channel is being used.
Watch out for conflicts between built-in IDE controllers and add-in
controllers. If you are using an add-in controller, for example
for enhanced BIOS translation support, then you need to make sure
you disable the built-in controller so that there is no conflict.
Watch out for sound cards that have IDE controllers built in to
them--this is quite common. Make sure the controller is not enabled
unless you are using it.
There could be a problem related to the IDE cable. If you have another
IDE cable, try replacing the existing one and seeing if this solves
the problem. Try a shorter cable if possible; long cables sometimes
cause problems. Make sure that the IDE cable is not being stretched
Some BIOSes fail very ungracefully when they are presented with
a disk that has a geometry including over 4,096 cylinders (over
2.1 GB). In some cases they will fail to detect the drive at all
(others may have a problem with these larger disks but they will
at least notice that the disk is there). Some BIOSes apparently
handle 2 GB disks OK but choke on hard disks over 4 GB. You should
investigate your motherboard's characteristics to find out if there
are any known limitations.
Some very old hard disks may not autodetect at all; they may just
not work on your system. This is quite unusual and not encountered
often with modern hardware.
I have seen a hard disk lock up and not be able to be recognized
by the system in some circumstances when paired with a CD-ROM drive
on an IDE channel.
Believe it or not, some older Compaq PCs used proprietary hard disks.
You could not just plug in any old IDE hard disk and expect it to
work. If you have an older Compaq (386 class) then you may want
to contact their technical support about a hard disk for it.
If after trying all of the above the hard disk still appears to
be dead, you should contact the technical support department of
the drive's manufacturer for more assistance. Sometimes there are
special situations that arise that the technical support people
may be able to help you with--for example, a drive may have a known
problem for which there is a workaround. You may also want to inquire
about the possibility of a replacement drive if it is still under