This driver works with the AOpen Rockwell PCI HCF modem - the part number on the card should be something like 91.12019.103, Ver BA, and it should have on the top right hand corner of the chip side "56VPCI-U/R".
This was downloaded on 17 Feb 2001 from the Acer Netxus web site - they call it an AMI-56VPCI modem. I assume AMI is for Acer Modem Internal - ??
I haven't tested this with Win2K, I simply uploaded the driver from Acer that was next to the one for Win98. I assume it works, I hope my assume does not make an 'ass' out of 'u' and 'me'. -)