While technically correct, this is not the actual reason.

Almost all versions of the ATI drivers have gone throught the WHQL process,
and anything that ATI/AMD posts to their website will be WHQL signed.

The reason that ATI does not want to post drivers to WU is because ATI does
not sell hardware directly to consumers. ATI/AMD sells hardware to
resellers and to OEMs, who in turn support the end user. If ATI were to
post a bad driver to WU, OEMs like Dell would get the support call. This is
the same deal for most hardware manufacturers.

Here is a useful bit of information related to PCI hardwareIDs:

The full PCI hardwareID of a device will contain information about who
manufactured a device, and who the manufacturer resold the device to:

Example:

PCI\VEN_10DE&DEV_0422&SUBSYS_C7353842&REV_A1

VEN_10DE is the PCI registration for NVIDIA INC. The Subsystem Vendor ID
(3842, in this case) is the company NVIDIA resold the chipset to. A visit
to www.pcisig.com (membership tab, vidsearch menu option) tells me that 3842
is the hex value for "eVGA.com Corporation". It is this corporation that is
really responsible for providing me driver updates.


"Rich." wrote in message
. ..
Because Microsoft only posts certified updates. Because of that you have
to wait until the new driver has passed the lab tests and gets certified
by Microsoft before they'll post it.


"md" wrote in message
...
When you use Device Manager to check for a new ATI driver, in this
case for an x1600 Pro, Windows Update reports the latest version is
installed version 8.391.0.0 dated 6/26/2007.

But according to ATI's Web site, the latest version is 8.9.

Why doesn't ATI push the latest driver to Windows Update -- so it
would be easy for everyone to make sure they have the latest driver --
and to easily install it?