Modem Problems

I have a 56k Pci Internal data/fax windows modem. Model # PCI15606. The Modem has been loade manually and auto without results. It has problems recognizing the moded with a port or IRQ this in not the only Modem we have tried this is the 3rd or 4th. Can someone help with getting this resolved to recognize Port and Irq. Any help will be appreciated. O/S windows 95. The machine meet all requirements for the modems we have tried.