HELP please - modem installed but not recognised

Hi

I recently had to reinstall Windows 98 and now my PC(Dimension 4100) will not let me connect to the internet as it says no modem is installed.

I have re-installed the modem drivers and the modem test works fine. The modem is showing in the hardware and in modems, but as soon as i try to add a new connection for my internet it tells me I need to install a modem and doesn't show the modem as being already there.

This is driving me mad - please can someone help!!!

Thanks