Calling all real XP experts

PROBLEM
I recently purchased and installed two PCI cards; one
card to provide a Firewire connection and a RAID
controller card. On start-up, the new hardware is readily
recognized by the OS (Windows XP Home) and the driver
installation procedure commences in the normal fashion.

However, the driver installation process always comes to
a premature end and fails with the following error
message:

"Cannot install this hardware
There was a problem installing this hardware:
IEEE 1394 Controller / RAID Controller [depending on
which one is being installed]
An error occurred during the installation of the device
The data is invalid."

The same happens when I try to install the hardware
driver manually in the Device Manager (the new hardware
is listed in the Device Manager with a yellow question
mark with the comment "This device is not configured
correctly. (Code 1)"). Updating or reinstalling the
driver always leads to the same error message.

MACHINE SPECS
- Intel Pentium 4, 2.2 GHz
- Intel D850EMV2 board with 850E chipset and dual RAMBUS
- 512 MB RDRAM
- Microsoft Windows XP Home, incl. SP1 and all available
updates

ATTEMPTS MADE TO SOLVE PROBLEM (to no avail so far)
- Searched Microsoft's knowledge database for solutions
- Found two partially relevant articles and followed
instructions to solve problem
- Made sure cards are properly seated in PCI slots
- Tried cards in different PCI slots
- Installed cards individually and together
- Downloaded latest hardware drivers
- Tried manual (advanced) and automatic driver
installation

I am at a loss what else I could try but there must be
someone out there who knows what to do. I would greatly
appreciate any help I can get.

Jorg.