Windows 2003 Network Monitor (netmon) Error

I have multiple Windows 2003/SP1 servers that give me the following error
when I try to start Network Monitor (netmon)

The system reported no protocol parsers! Please reinstall, Network Monitor
requires protocol parsers.

This happens with either the built-in Network Monitor or the Full SMS 2003
Network Monitor (2.1). I have reinstalled many times with no luck; any help
would be appreciated, as I can not find much information on this error with
Internet searches.

Thank you in advance for any help!