I have a Dell Dimension which dual boots Windows XP & Mandrake & I'm having problems trying to get my hard drive recognised again by the BIOS.

It was working OK before the issue I describe below & I've not made any hardware changes

Here's the sequence of events which got me to this point:

After performing a windows "chkdsk /r" on my C: drive (win XP), the machine wouldn't reboot.("F1 to retry, F2 to enter setup")

At this stage the Hard drive, dvd & cd-rom were still recognised; so I booted from a Suse Live cd & tried to use Grub to rewrite the MBR which I thought might have been damaged by checkdisk.

Rebooted, Hard drive, dvd & cd-rom were now not recognised in BIOS, listed as "not installed" & "unknown device"

I discovered that by turning off the hard drive in the BIOS & rebooting the dvd & cd-rom were recognised.

Booted Suse Live, dmesg showed my hard drive & fdisk listed my partitions:

Disk /dev/hda: 40.0 GB, 40020664320 bytes
255 heads, 63 sectors/track, 4865 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/hda1 * 1 1305 10482381 7 HPFS/NTFS
/dev/hda2 1306 4864 28587667+ f W95 Ext'd (LBA)
/dev/hda5 1306 3855 20482843+ b W95 FAT32
/dev/hda6 3856 3868 104391 83 Linux
/dev/hda7 3869 4799 7478226 83 Linux
/dev/hda8 4800 4864 522081 82 Linux swap / Solaris


So, even though the the Bios couldn't see the hard drive (& it was turned off in the BIOS) Suse Live did
I mounted my Linux partitions & used Mandrake's Grub to re-write MBR:

root (hd0,5)
setup (hd0)
quit

Rebooted. F2 to enter setup
Hard drive was now seen in BIOS.
Exited & mandrake started OK (when exiting BIOS, system seemed to bring up Grub menu immediately without a restart as usually does)

However, this was a false dawn. Next time I came to startup, I was back in the situation where no drives (except floppy) are recognised in the BIOS.

I turned off the hard drive & got the other drives back as before.

Booted the Linux Live cd, but this time there's no sign of hard drive from that either.

eg, cfdisk gives "fatal error: cannot open disk drive"
& when try to mount hard drive says it's "not a valid block device"

HELP!

That's really weird that a piece of software, like SuSE, would see you drives, but the BIOS won't, considering that an OS would get HD info from a bios. Maybe it has something to do with master/slave settings on your drives? You may also want to check the hookups (what controllers they're plugged into, etc?) I know from experience that Linux is a lot less picky about these things that Windows is.