Asus EN8600GT Graphics Driver Problems - Help Please

I just put together a brand new system with an Asus P5K main board, an
Asus EN8600GT Silent Graphics Card with 512MB video ram (Nividia Chip)
and 8GB of DDR2 system Ram.

I am running Windows XP SP2 and all drivers for both the onboard
mainboard components and the graphics card installed properly without
error. I am also running a dual monitor setup with the card.

Shortly after the install XP started downloading and installing updates
and then I started having problems with the graphics card driver.

Basically every time I restart the computer or power it up with a cold
boot the display driver reverts back to the original XP default driver
(which of cource is not able to support the card properly). Then XP pops
a message telling me the current manufacture’s graphics card driver I
have installed can’t be used anymore and that I need to download and
install an updated version.

So I went to the Asus web site and downloaded the latest release of the
Asus EN8600GT VGA Driver for XP, which is version 169.21 dated
12/05/2007.

Then, once I put the driver update in, the system asks to reboot and
everything is fine again with my 2 displays.

But as soon as I either restart or shut down and reboot I am back to
square one with the same problem again.

Anyone have any ideas on how to fix the problem?

Many thanks,

Marc