Have installed win98se on Asrock 775Dual-VSTA.

http://www.asrock.com/mb/overview.asp?Model=775Dual-VSTA

This board has:

- Via PT880 Pro/Ultra northbridge

- Via VT8237A southbridge

I'm seeing a yellow (!) in device manager for this:

System board extension for ACPI BIOS

This device is causing a resource confict (code 15).

According to the Driver tab, the provider is MS (4-23-1999) and under driver file details I see this:

\system\vmm32.vxd (configmg.vxd)

Vmm32.vxd is dated (modified) as Feb 10/2007. File creation date is listed as "unknown", and I can't get any version info about it.

I believe that Feb 10, 2007 is the install date for win-98 on this system, which makes me think that this file was assembled or fabricated during win-98 installation or subsequently as part of device detection and driver installation.

In the Resource tab, I see 4 memory ranges, but the last one is showing the conflict:

Memory range: FFF80000 - FFFFFFFF

I can remove the checkmark in the "Use Automatic Settings", but it won't allow me to manually change the memory setting ("This resource setting cannot be modified").

In device manager, there are 3 items listed simply as "motherboard resources". One in particular has maybe 10 or 20 entries in it's resource list, all but 2 of those are I/O addresses, the other 2 are memory ranges. One of those ranges is this:

Memory range: FFFFFFF0 - FFFFFFFF

Which obviously overlaps with the range for the ACPI device above. Again I'm not able to change that range manually.

Another device (SCI IRQ used by ACPI bus) is listed as ok.

Any ideas on how to resolve this ACPI conflict?

Try to disable evey "power support" items in BIOS. You can also uninstall the yellow marked device and reinstall ULI's drivers.

Tihiy posted a reg file to disable ACPI support some time ago but since I can't find the link anymore but still have it on HD, here's the entry to modify:

[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\Current Version\Detect]
"ACPIOption"(dword)=2

HTH