The Agere Systems PCI Soft Modem is a software-based modem that allows your computer to connect to dial-up internet services using a PCI (Peripheral Component Interconnect) card. It uses the CPU of the computer to handle modem operations, making it a "soft" modem as opposed to hardware modems that handle the processing on the modem itself.

The Agere Systems PCI Soft Modem Windows driver is the software needed for the modem to function correctly on a Windows operating system. Without the proper driver, your computer may not recognize the modem or be able to use it for dial-up internet connections.