I have a KG7-R and never got any ACPI error messages...
first of KG7 is fully ACPI compatible mobo, so I don't know why you're getting an error message... if I were you I would contact ABIT rigth away...
In Win2K disabling ACPI is the easiest thing, but remember there's no turning back... If you want ACPI back, then you need to make a fresh install... Go to your "Device Manager" and under "Computer" change "Advanced Configuration and Power Interface (ACPI) PC" to "Standart PC", just like u normally update a driver... Don't forget to choose "Display a list of known drivers..." though ;0)
For more info visit the Paul's Unofficial KG7/KR7A FAQ...
http://www.viahardware.com/faq/kg7kr7/kg7kr7faq.htm
Good luck