After Microsoft's install is done, it's left to the installer (you!) to install drivers for motherboard, video, audio, USB, modem, printer and what have you. Many only learn that Microsoft provides the OS, and you provide the rest after they format.
Generic modem drivers rarely work today. You'll want to find the proper driver for your modem. But motherboard drivers are likely needed before that works for many systems.
You didn't tell about the machine, so no one can help you find said drivers.
I thought ZoneAlarm may have caused a problem, that it had caused previously, and I was unable to connect to the internet, but having tried every solution I could think of I reformatted the disk and reloaded Win98 SE.
I still can't connect and now Windows doesn't recognise that a modem is installed, which should not be a major problem because I normally use a router on a broadband connection. However when I ping the router it fails or some packets are lost; I have tried rebooting the router. The network card's LED is alight and Windows reports that it is working properly
Also Windows has automatically loaded a generic driver for the monitor but I need to change it to one I have on a disk but Windows doesn't recognise it although it has done previously.
Any help appreciated.