In my experience with modems, and drivers, it is much better to just go and buy another PCI modem, checking with the store that it comes with drivers for the operating system that you are using.
It will cost about £15 for a modem with an intel chipset from a discount store.
I have found that it is possible to spend days looking for drivers, downloading and testing them, and where modems are concerned, it is often a waste of time.
You could try the dell website, but I have had a bad experience here with their modem drivers.
