A FEW models of DSL/Cable modems also include router functions, but most do not. Yours does not. And since your modem does not have drivers available for Linux, your options are:
1: Stick with the modem you have and switch to Windows when you need to use the Internet. If you do this, PLEASE make sure you install a software firewall on your computer in both operating systems to help keep unwanted 'visitors' out! Result: Internet in Windows, not in Linux.
2: Find a cable/DSL router that supports connection to a USB modem (I don't know of any personally but I wouldn't be surprised if somebody makes one), connect the modem to the router and have the router log in to your ISP through the modem, connect your PC to the router on a LAN port using an ethernet cable and a standard network adapter card in the PC. Result: Internet in Windows and Linux without needing a new modem from your ISP, connection can be shared with multiple computers if needed, router provides firewall protection for your home network.
3: Get a modem with an ethernet port and connect it directly to your computer using an ethernet cable and a standard network adapter in the PC. If you do this, PLEASE make sure you install a software firewall on your computer in both operating systems to help keep unwanted 'visitors' out! Result: Internet in Windows and Linux.
4: Get a combination modem/router from your ISP that has at least one ethernet port that you can use to connect your PC to the router for Internet access. Some ISPs will do this, some won't. Result: Internet in Windows and Linux, connection can be shared if you get a modem/router with more than one ethernet port.
5: Get a modem with an ethernet port and connect it to the WAN port on a cable/DSL router, connect your PC to a LAN port on the router using an ethernet cable and a network card in your PC. Result, Internet in Windows and Linux, connection can be shared with multiple computers, router provides firewall protection for your home network.
Obviously, #1 is the cheapest and simplest since you won't be changing anything at all other than installing a software firewall program, but you won't be able to use the Internet when you are running Linux.
The preferred method would be #5, but it also requires you to spend some money for the router. #2 would be simpler than #5 with simimilar results, but you might have a hard time finding a router that will let you use your current USB-only modem...
If your ISP will support it and will provide the hardware (possibly for a small fee), #4 might be the best option since you'll have hardware that is completely supported by the ISP. The firewall functionality of the modem/router combo units is minimal at best, but it would be vastly superior to the USB modem you are running now with no software firewall on the PC. If you do go with this option, I would still recommend installing a software firewall in both operating systems on the computer since the router function in a modem like this only provides very minimal protection from intruders.
edit: Had to fix the inevitable typos in a long post like this one.
