Unfortunately, none of those 3 methods you mentioned worked for me. My network is setup as such: My dad's computer (rarely even on, running XP), my mom's laptop (also running XP), and my computer (which is running XP) are all connected to a Linksys BEFW11S4 router. If you didn't know, that router is a wireless one, but im not on a wireless connection. My mom's laptop and my computer are wired into the router (my dad's computer doesn't even need to be worried with, its off 95% of the time). I know more about computers than either of my parents and the only reason i want to get to router is so i can access the internet through knoppix. I also made the mistake of mentioning PPPoE - i shouldn't have said anything, im not on DSL. Seeing as how I didn't know anything about Knoppix i was just messing around with all the configuration utilities and I just happened to mention that one in the post. Heres something strange though, Now that i have tried to use Knoppix to get on the internet and tried to get these configurations to work, i can't access my router. I know exactly what your talking bout, Im very familiar with the menus in my router and kknow for a fact that DHCP is enabled. I don't need an account with my ISP to get online, I use RoadRunner.
When i tried "sudo mii-tool -r" at the prompt, it gave me the following message:
SIOCGMIIPHY on 'eht0' failed: Invalid argument
no MII interfaces found
I typed exactly what you said to, then the netcardconfig utility continued to fail on me. Im really starting to like Linux, with the exception of all this internet config, and would really like to get this working. Thanks for all your time trying to get this straight. Any other advice?

PS: Im using 3.4 Knoppix

EDIT: I think i entered the wrong IP address for my machine during the netcardconfig. I put in one that matches the result of ipconfig in windows, and when i typed in "sudo mii-tool -r" at the prompt it said: "reconfiguring autonegotiation" (or something very similar). Unfortunately, when i ran netcardconfig, the DHCP broadcast failed and the internet still isn't working.