I solved the issue of Intel ProSet not removing itself by manually running the uninstall string defined in the registry under HKLM\Software\Microsoft\Windows\Current Version\Uninstall.
This removed the Teaming software and drivers. On one machine I had to do this from within Safe Mode.
Reinstalling the original version of ProSet did not work. It resulted in the same outcome (TEAM NIC unable to start and displaying as yellow exclamation).
Having removed the offending version of ProSet, I installed the latest compatible version of ProSet that was acquired directly from Intel website.
All is well.
It was Server 2K3 SP2 that caused the incompatibility.