Original modem

I installed a new modem that, unfortunatly, stopped working, so I returned it to the store. I put my original modem back in. When I bought my PC, Win 98SE was the only OS on the hard drive. I bought a larger hard drive, partitioned it, reinstalled 98SE on C: and XP Home Edition on D:. XP works fine with the original modem but 98SE, the original OS that was used with that modem when I bought the PC, cannot identify it.I’ve gone into Device Manger, checked all the settings, IRQ’s, I/O addresses, etc.. and somehow the modem got set to COM 5. How can I change the modem settings so it will work with 98SE again?
Thanks, Jim