PC continually detects wrong modem.

Hi, I would appreciate your assistance.
My internal modem has been physically removed and has been replaced by an external modem.
I have removed the internal modem from the control panel and installed the external modem with a cd rom.
However my problem is everytime I reboot the PC it detects the internal modem and and then installs it.I am then required to reinstall the external modem.
Running WIN2000.
Internal modem Lucent.
External modem Diamond voice.

Is there a bios or registy setting that I can change so the system will detect the external modem every time?

Thanks in advance
Ren