modm drivers for 33.6 upgradble compaq

I haved tried to take a compaq pressario 4010(?) modem and tried to refit in another compaq machine,I have tried the usual drivers, but cannot get the second machine (running win 95) to recognise the modems presence. the modem is an ISA lucent chipset
Phone dialler message is modem in use by nother program. modem add wizard message is no modem found please help otherwise this modem gets it in the head!!!