I have a PC that dual boots 98 and NT4 (SP6a). PC has operated in this environment for 3 years without problem. I have installed XP Pro on this PC so it now triple boots. All 3 o/s are installed on separate logical drives. XP also runs without problem. Only problems I have is PC now starts back up about 20 mins after power down. Also, when PC is powered down (via pwr switch on the box), the user has to engage the switch for 4 secs before power down occurs. The BIOS does have a setting Soft-off-by-Power-button, either instant-off or delay-4-secs, but this has always been set to instant-off. I initially thought these 2 issues were a result of ACPI incompatibility between XP and motherboard.
Motherboard is an MS-6153 and the BIOS does support ACPI (enable or disable). ACPI has always been enabled in BIOS as Win98 uses it. The board supports Wakeup on LAN, Power on by Ring and Resume by Alarm, these options have always been disabled in BIOS.
ACPI was enabled in the BIOS when I firstinstalled XP. The PC restarts itself after power down from an XP or NT session, but not from Win98 . This is understandable as XP install replaces NT4 versions of ntdetect and ntldr (and boot.ini) with it’s own versions. I cannot boot to XP if I disable ACPI in the BIOS (PC hangs at XP startup).
Rolled back to pre-XP by replacing ntdetect, ntldr and boot.ini with the NT4 versions and formatted the drive where XP was installed. Then a fresh XP install, this time using F5 to specify PC as a standard PC (i.e. non ACPI). After this install both problems still exist. Rolled back to pre-XP again, disabled ACPI in the BIOS and another fresh XP install, again using F5 to specify standard PC. Same 2 problems exist after this install. This leads me to believe that ACPI is not the problem as I have disabled it in the BIOS and forced XP to ignore it during install. Anyone have any ideas on what might be the cause.