This looks to be remarkably similar to an issue I'm pursuing.
I've just reformatted the disk, and installed a fresh copy of Windows XP
Home SP2. The PC still freezes (this has been an issue for quite some
time). There seems to be a regular pair of events in the System event log
that accompanies such a freeze:
Event Type: Error
Event Source: ACPI
Event ID: 5
Description:
AMLI: ACPI BIOS is attempting to write to an illegal IO port address
(0xcf8), which lies in the 0xcf8 - 0xcff protected address range. This
could lead to system instability. Please contact your vendor for technical
assistance.
The other is the corresponding 'read' event.
The corresponding link to Microsoft's site gives the following
information:
*********************
Product: Windows Operating System
Event ID: 5
Source: ACPI
Version: 5.2
Symbolic Name: ACPI_ERR_AMLI_ILLEGAL_IO_WRITE_FATAL
Message: %2: ACPI BIOS is attempting to write to an illegal IO port
address (%3), which lies in the %4 protected range. This could lead to
system instability, etc.
Explanation
The system BIOS attempted to incorrectly access hardware resources
concurrently with the operating system. This type of access cannot be
synchronised and can cause system instability.
User Action
Contact the system vendor for an updated BIOS and follow the vendor's
instructions for installation.
*********************
I cannot seem to find a suitable BIOS update, but am awaiting a response
from the system vendor.
However, following a comment in another forum, I changed the Plug and Play
Operating System setting in the BIOS to No/False. This setting is
recommended in a Microsoft article
(
http://support.microsoft.com/default.aspx/kb/314068) anyway. Following
that, I was able to run the PC for a good couple of hours as it downloaded
and installed a large amount of updates from Microsoft Update. It hasn't
frozen since, but as that was only last night, I can't be certain of
success yet. However, prior to that, the PC was freezing so frequently as
to be unusable; it was freezing pretty much immediately on trying to run
updates from Microsoft Update, and also trying to install an update from
another site, so there has been a definite improvement.