Support Information:
Device Type: Modem / ISDN
Manufacturer: Compaq
Model: Microcom 550
Interface: PCMCIA
Operating System: Windows 2000 Workstation
Age of Device: Not specified
FCCID: CNTMLA-32898-M5-E

Find it on DriverGuide (http://members.driverguide.com/index.php?action=srch&sm=b&aax=&qa6=236&qa5=10&qa7=1700&dp=3&qm0=Microcom+550&jmd=and&fzz=d) | Find it with Google (http://www.google.com/search?hl=en&lr=&ie=UTF-8&oe=UTF-8&q=Compaq+Modem+%2F+ISDN++Microcom+550+Windows+2000 +Workstation+CNTMLA-32898-M5-E) | Research manufacturer Compaq (http://members.driverguide.com/index.php?action=getinfo&companyid=236)

This device was only supported in Windows 3.1x, 9x, NT4.0 OS. To my knowledge, there were never any drivers written for Windows 2000. However, the NT4 driver should work fine.

http://download.modem-help.co.uk/mfcs-C/Compaq/Microcom-550-Combo-56K-Modem-Ethernet-PC-Card/