PCI Device Detection

[Guest]

I created a PCI device that worked fine in Windows 2000, XP SP1, and XP SP 2
until I tried to deliver one to a customer. In their Windows XP SP 2
machine, windows would not detect the device. It IS configured in PCI space,
I can even read the onboard memory, but Windows will not detect it. I
removed all other PCI devices that shared the PCI bridge my card was on with
no change.
What would keep Windows from detecting new hardware like this?

Clint

 

[Guest]

Following up:
I found a couple of the PCI configuration registers were not read-only, but
should have been. Computers will evedently write something in these
locations if the device allows it. It ends up being a different value
depending on the computer and/or configuration. One of the registers was the
Type Header. Apparently Windows will not detect a device with an illegal
Type Header (unless only the MSB is set). Making these registers read-only
took care of the problem.