Is this a DSL modem or an actual modem?
Cabling should look like:
PC<-->Hub<-->Amiga
Cables should be non-crossover; some hubs can autosense and adjust, but as usual, it's good to reduce variables. Some hubs also have a switchable or permanently crosswired "uplink port;" plug your non-crossed wires into normal ports only, please.
Easy way to tell a crossover cable: Look at the connectors from the top (non-clip side). A normal "straight through" cable will have the same color wires on pins 1 and 2 on both ends (first two pins on the left... they get paired up as a solid and stripe pair, so just look at the one that you can see color on). A crossover cable will have different colors, because the pairs are crossed.
---
To actually use "Internet Connection Sharing," you need to activate it somehow. It's an optional component, so if you have 98SE and can't find it in the Start Menu (Control Panel submenu?), you need to add it as an option, I forget how the heck you do that but I think it's under Add New Software in the Control Panel or something, then Add/Remove Windows Components.
---
If this is a DSL modem, you're best off getting a generic router (Linksys, 2Wire, whatever's cheap at the drugstore this week) and not having to think. If it's a regular modem and you don't want an excuse to get rid of dialup, yeah, you're a bit stuck, though if you want to throw money at the problem, a similar US$50 can get you one of these if you can find one:
Actiontec home router with 56k modem ...
which can make an entertaining geek toy, too.---
Edit: The discontinued 3Com 3C510 apparently is/was another cheap home router with a modem.
This article mentions similar SMC, Asante, and GVC products, which might be more readily available wherever you are.
---
Double-Edit: The 3Com 3C888 is a bit overkill, but was available in Europe, and
there's one going for 0.99 of your monetary units on eBay.co.uk. Note that
it is a standard router, should be no problem using it with Macs or Amigas despite the seller's confusion.
Of course, if you get ICS working, that'll work too, but I can say that, if you can afford it, it's worth buying the hardware so you never have to waste your time on it. Always a good idea to get your Windows-machine-securing firewall offloaded to less-exploitable hardware, too.
