I am just a home user, and not an "IT guy".
My recommendation would be, to look through your collection of
spare disks. Disconnect the working disk, connect a spare disk,
install WinXP Home SP2 OEM. Then activate it. Now, you have a
bootable solution, if you need it or want it. By keeping it
totally independent of the working disk, you are reducing the
risk of having nothing working.
I am not as pessimistic about SATA, as Mayayana. The
basic idea is this:
1) In your computer BIOS, the disk interface has a variety of
settings. These SATA port settings include
IDE - Enhanced or Compatible on an Intel chipset
AHCI - Supports Hot Plug for data drives, and Command Queueing
for performance. The queuing option comes in handy for
server workloads, less for desktops. None of my systems
run with the BIOS set to AHCI. If you have an SSD drive,
then AHCI is a great choice (due to TRIM support in some
cases). My systems are generally set to Enhanced IDE.
RAID - used for multiple disks, not important at the moment.
Usually, the default choice in the BIOS, has decent compatibility.
You may not need to change anything. And if you have changed
that setting, chances are you know all about this stuff anyway.
2) The OS has some built-in drivers. And each Service Pack level,
has some rules for large disks. The later Service Packs support
large disks. The easiest way to see this, is say, plug in a
320GB disk. When the install CD is running, if it refuses to
make C: bigger than 137GB (the "size barrier" value), then
you know you have a problem. You can still complete the install,
just not put partitions above 137GB. If you end up this way,
come back for suggestions.
The drivers can include the IDE ones. They're the most likely to
Compatible mode, makes the motherboard look similar to an older
motherboard, with two ribbon cables. Up to four disk drives can
be supported that way, and an old OS thinks the SATA drives are
actually on ribbon cables. But compatible mode, limits the number
of disks. Now, some motherboards only have four SATA ports, so this
may not be a big deal. My motherboard has six SATA ports, and
selecting compatible, and mapping the disks to I/O space, wastes
the other two ports. The other two ports would be disabled if
I ran that way.
Enhanced maps the ports to PCI space. You can support as many disks
as there are connectors in that case. PCI space means, in a way,
that it is like the motherboard ports, were on a PCI SATA card.
They'd look roughly the same, in a sense.
Anyway, check your BIOS. You do that, just after powering up the machine,
and pressing the key that gets you into the BIOS. On my Asus machine,
that would be the <DEL> key. On my Asrock, it is press F2. Look through
the BIOS settings. Chances are, the disk mode is something that
your WinXP CD will just install on.
No big deal if it fails. You can plug the original disk back in,
use the original settings (if you have made changes), and it should
all come back. If you change anything in the BIOS, either take
a picture of the screen with a digital camera, or write down
the original settings.
I do not recommend trying to install WinXP OEM, on the same disk
that has the working but cranky current install. If you keep the disks
separate, you can experiment as time allows.
Depending on your symptoms, hardware details, maybe someone here
will remember something that can help you further.
So really, the biggest part of the deal, is your ability to handle
unplugging the current disk, and fitting another. And of course,
verifying that the new disk, to be used for the install, has
enough room, and does not have any valuable data on it. Sure,
you can install on a disk that has data, make a new partition
and so on. But also remember, that the installer CD can trash
the partition table - I had that happen last week, while playing
with a Win2K installer CD. I exited from the installer, after
examining what the partitioning options might be, and thought it
could not possibly have made any changes. But it had, and it
zapped the partitions on the disk. I used TestDisk to put back
the partition table (a tool that scans the disk, then rebuilds
the table). But as that is a damn scary tool to use, you really
do not want to be in that situation. If you grab a disk with
nothing of value, to do your OEM install, then you will have no
I have not a clue what would happen, if a Home installer disc
was used to Repair Install a Pro version on C:. I expect it
would be ruined, but stranger things have happened.
One other tiny note. When you buy a disc in North America,
the Microsoft Activation server will have an expectation
that the disc will be used in North America. If via geolocation,
they see you activating from PangoPango, that naturally rings
alarm bells, just like if a credit card charge was filed
in Germany, on my Canadian credit card. You may end up,
needing to phone a human, to complete activation. And I do not
know if they will make a nuisance of themselves or not. I am
only mentioning this, so you will be mentally prepared. Since
you are playing around with a second, unused disk, if you
meet any kind of resistance, it is not the end of the world.