Modem not recognized

I have installed a PCI v90 56k modem on a 486dx 4 machine. I went into the bios and disabled com2, then changed the I/O settings for the modem in the system properties. the modem worked fine once I did that. However the problems started when I rebooted the computer. Now it sees the modem but when I try to connect to the internet, dial-up networking says that there is no modem installed. When I go into the control panel and run a diagnostics on the modem it responds that the port is open. Any suggestions?