SATA boot problem - looking for advice

....or at least an understanding of what's happened...

My WinXP machine came with one 300Gb Maxtor SATA drive, and I've
since added another, on which I have data only. Following a couple of
lock-ups and the subsequent forced reboots, I suddenly found myself
staring repeatedly at a message telling me "no OS or system disk
found". (The lockups are understood, and were down to a clash between
the latest World of Warcraft patch and an out-of-date UI mod).

In trying to get the machine on its feet again, I discovered that the
(arbitrary) connection of drives to SATA cables meant that the BIOS
sequence was looking at the data drive first, followed by the older
(on which the OS resides). And, if I reverse the boot sequence by
changing cables around (I haven't actually tried modifying the
sequence in BIOS yet), suddenly everything works again. Not only
that, but running PartitionMagic 8.0 under Windows doesn't show up any
problems with either disk - all partitions are there, and so forth,
and the associated PartitionInfo utility (which seems intended to
capture diagnostics) doesn't report anything wrong either. The DOS
PQMagic boot diskette, by contrast, shows an error #110 on the data
disk - "the hard-disk partition contains two inconsistent descriptions
of the number of sectors on the hard disk". A full virus scan finds
no threats.

I'm guessing that what's happened is that the MBR on the data drive
has become partly corrupt, but I don't pretend to understand these
things well enough to know why that might allow continued data access
but prevent a boot continuing to the next device, nor whether it's
something I should be worried about, or just accept as a fact of life.
Can anyone clarify/advise me? And (hypothetically at least, because
"leave well alone" is one serious option here), how would I go about
fixing something like that without wiping the existing partitions (I
have 150GB of data on it that I *could* lose but would prefer not to,
and no obvious place to back it up to right now...)?

Cheers - Ian

You might disconnect the second drive until you get it figured out.

Does the owners manual for the motherboard say anything about SATA drives,
as far as what controllers you might need, or what the bios should be. My
present computer needs a Raid controller enabled to use SATA. You might
check for things like that, and maybe which SATA connector has priority, if
any.

I also know of one computer manufacturer that seems to supply substandard
SATA cables, so you might look into getting some perhaps better ones.

Clark

"Ian Noble" wrote in message
...
...or at least an understanding of what's happened...

My WinXP machine came with one 300Gb Maxtor SATA drive, and I've
since added another, on which I have data only. Following a couple of
lock-ups and the subsequent forced reboots, I suddenly found myself
staring repeatedly at a message telling me "no OS or system disk
found". (The lockups are understood, and were down to a clash between
the latest World of Warcraft patch and an out-of-date UI mod).

In trying to get the machine on its feet again, I discovered that the
(arbitrary) connection of drives to SATA cables meant that the BIOS
sequence was looking at the data drive first, followed by the older
(on which the OS resides). And, if I reverse the boot sequence by
changing cables around (I haven't actually tried modifying the
sequence in BIOS yet), suddenly everything works again. Not only
that, but running PartitionMagic 8.0 under Windows doesn't show up any
problems with either disk - all partitions are there, and so forth,
and the associated PartitionInfo utility (which seems intended to
capture diagnostics) doesn't report anything wrong either. The DOS
PQMagic boot diskette, by contrast, shows an error #110 on the data
disk - "the hard-disk partition contains two inconsistent descriptions
of the number of sectors on the hard disk". A full virus scan finds
no threats.

I'm guessing that what's happened is that the MBR on the data drive
has become partly corrupt, but I don't pretend to understand these
things well enough to know why that might allow continued data access
but prevent a boot continuing to the next device, nor whether it's
something I should be worried about, or just accept as a fact of life.
Can anyone clarify/advise me? And (hypothetically at least, because
"leave well alone" is one serious option here), how would I go about
fixing something like that without wiping the existing partitions (I
have 150GB of data on it that I *could* lose but would prefer not to,
and no obvious place to back it up to right now...)?

Cheers - Ian