I know I'm a little late, but here it is anyway....
Just for your knowledge. Network devices/Modems are all unique. They all have a unique hardware number that makes them different and that is why you can have multiple devices in a computer and they can be installed all at once...also, they use different interrupts and memory addresses...
There is one thing...In Windows95/98/2000 operating systems...If you have a network adapter and it obtains an ip address from a DHCP server or from a network dynamically, the ip address of your ethernet adapter will be overridden by your cable modem or analog modem. If you wish to share your connection and you have Win98SE or WinNT/Win2K you can setup Microsoft Internet Connection Sharing or the NT/2K equivalent(a couple of ways to do it) to share your connection to client computers and you should have no problems unless you don't have your network adapter installed correctly. In Windows95/98, the best way to check your card to see if it's installed correctly is to make sure you have the TCP/IP protocol installed and run WINIPCFG. What this will do is allow you to read your adapter address off the card. If you can read it, 99 times out of 100 you're card will be setup correctly and you'll be able to use it for whatever you need to. Good luck. I wish I could be of more help and if any of this is too confusing or badly worded, I apologize, I'm a tech....I do a better job working with this stuff than I do explaining.