[Ham-Computers] RE: WINDOWS XP doesn't see HD

[Hsu, Aaron (NBC Universal)]

Don,

Sorry for getting in on this so late...for various reasons, I don't check my
work e-mail over the weekends anymore.

Based on the other suggestions and your answers/results, it seems that you
may have originally formatted the 30GB drive with some type of formatting
utility (such as Ontrack's Disk Manager).  Drive formatting utilities were
the norm for a few years as many systems didn't recognize the full capacity
of the drive due to BIOS or OS constraints.  To get around these
constraints, an "overlay" was used to "outmaneuver" the BIOS drive capacity
recognition system.  This overlay was added to the boot sector on the drive
and loaded before the OS.  Basically, it was a small program that handled
access to the drive since the BIOS was unable to directly do so.

Unfortunately, overlays were proprietary to each drive utility and usually
not compatible with other overlay utilities or the native BIOS disk
handler(s).  This means that in order to access the data on a drive with an
overlay, you need to be running the overlay software.  Of course, the
overlay software is in the boot sector, so unless you booted off the drive
with the overlay software you wouldn't be able to read the data from it.
One way around this is to use the same overlay software from the original
drive to format the new drive.  Unfortunately, this will cause the same
problems again down the line when you get another new drive.  On top of
this, the overlay software may have been "keyed" specifically for a
particular brand or model of drive.  This is especially true of "free"
overlays that are bundled with hard drives.  You could spend the $100 or so
to buy the "full" version of the software, but this incures an expense
that's usually not worth it.

Overlays are only required if your BIOS doesn't support the full capacity of
the drive.  Several years ago, 8GB was a common BIOS limit that would
require an overlay for larger drives.  Then 32GB, and more recently, 127GB.
If your BIOS supports the capacity of the drive natively, then you should
*never* use overlay software.  It's just too much of a headache.  Instead,
look for a BIOS update for your motherboard to support the larger drive
sizes. 

In your case (if your BIOS can natively handle 40GB), the best bet is to
first install the new 40GB drive as the secondary drive and use Windows XP's
disk manager to initialize, partition, and format the drive (as a Primary
partition with one logical drive letter - choice of FAT32 or NTFS is yours).
Then install just the 40GB drive (as the primary drive) and install Windows
XP.  Once XP is installed, put the 30GB back as primary, 40GB as secondary,
and copy only what needs to be saved to the 40GB drive (in a
sub-folder...don't put them back in the original location!).  Once done, put
the 40GB back as primary, 30GB as secondary, boot into WinXP, and
re-initialize/partition/format the 30GB drive as a "native" drive without
any overlay software.  Once done, you can then copy the data back from the
40GB sub-folder where you backed everything up.

One note: if you can find the original disk utility that installed the
overlay, there might be an option to remove the overlay from the boot
sector.  If so, do it...this will ensure that the overlay will never be
loaded again.  The only other way to do this is to format the drive with a
low-level utility that will wipe the boot sector - something that needs to
be handled carefully.

Yes, sounds like a lot of work and this explains why I don't like overlays.
Quick fix at first, but a nightmare when more changes need to be done.

Good luck!

  - Aaron, NN6O


-----Original Message-----
From: ham-computers-bounces at mailman.qth.net
[mailto:ham-computers-bounces at mailman.qth.net] On Behalf Of Don
Sent: Friday, February 04, 2005 7:03 PM
To: Ham-Computers
Subject: [Ham-Computers] WINDOWS XP doesn't see HD


background
computer has a 1.9 gig amd athalon processor
512 MB ram
win xp with sp2 installed
a 40 gig pri master and a 30 gig pri slave

bios see both hd and the setting are auto auto on both
in the boot process it sees both hd
the device manager sees both hard drive and say both are working

however when I use windows explorer I only see the 40 gig pri master and my
2 CD drives and my floppy drive

how can I get the 30 gig slave to show up using explorer

thanks much in advance