Looks like I'm having a good old fashioned IRQ conflict. Even though IRQ's
are theoretically shareable these days, in practice it may not be such a
hot idea. The problem first occurred after I replaced my motherboard and
processor on one of my systems, a couple of weeks back. I was getting a
BSOD once every couple of days. I've had 5 BSODs so far. There has been 3
different types of Stop messages: variously involved the
DRIVER_IRQL_NOT_LESS_THAN_OR_EQUAL (twice), the BAD_POOL_HEADER (twice),
and the UNEXPECTED_KERNEL_MODE_TRAP (once) errors.
Initially, they involved TCPIP.SYS and IPNAT.SYS, both of which were
network-related. So I thought it's a network card issue and I updated the
Realtek Gigabit Ethernet driver, but that didn't help.
Then a couple of days ago, I got another BSOD, but this time it involved
the driver NV4_MINI.SYS, which is an Nvidia video card driver -- seemed
completely unrelated. Then earlier today, I got another
DRIVER_IRQL_NOT_LESS_THAN_OR_EQUAL error, and this time it came from both
the TCPIP.SYS and the NV4_MINI.SYS drivers together! That clued me into
the idea that perhaps these two are sharing the same IRQ. I looked in
Device Manager, sorted it by Resource Connections, and sure enough the
gigabit ethernet and video card are both sharing IRQ 18! And that's not
all, there's 5 other devices sharing this same IRQ too! Seven devices on
the same IRQ line! There's only one other line, IRQ 16, that has multiple
devices on it too, at comparatively paltry 3 devices. Every other IRQ line
that is used only has one device on it, and there are several empty unused
IRQ lines all over the place.
So I went into the BIOS settings, but couldn't find any IRQ setting
functions available to it. The only option I found was something that
either enabled or disabled Plug'n'Play OS support, but not much else.
I tried to go into Windows' Device Manager to manually configure the
IRQ's, but the manual setting of resources was grayed out. According to
this webpage, you can't manually set anything inside an ACPI-compliant PC:
"You may find you cannot manually change your IRQ settings (the Use
automatic settings will be greyed out), this is usually related to the
ACPI function used by Win XP. "
http://www.helpwithpcs.com/upgrading/change-irq-settings.htm
So now I'm stuck, is there some kind of program available to reset the
ACPI tables? Some sections of the Registry that I can change?
Yousuf Khan