Looks like you have a plug-and-play contention problem of some sort. W2K uses Advanced Configuration and Power Interface (ACPI) rather than Plug-and-Play to determine how to assign resources such as IRQs and IO Base addresses to hardware on a machine. But it will also defer to PnP if the PnP BIOS is enabled.
So, the first thing you want to do is turn off Plug-and-Play in BIOS. This gives ACPI free rein. You should also take everything off the serial ports. Sometimes special attachments can cause Plug-and-Play Manager to get confused.
If that doesn't work, or you don't have the option to disable PnP, then try stripping out all peripherals and boot again. This includes disabling all integrated peripherals except for video. If it's a laptop, jerk all the PCMCIA adapters from the slots. If this solves your problem, then put the components back again, one after another, until you find the culprit.
If you strip the machine to hull metal and it still gives this behavior, you'll need to determine if it is fully compatible with W2K. If it was built a few years ago, between 1997 and 1999, the ACPI chip might not be fully compliant. This is especially true if the machine is a laptop.
This was first published in May 2001