so i was having issues connecting to xbox live ..so i was trying to determine what the problem is...

i connect the cord from my modem to pc and it partially works.  i cant seem to browse the internet with the cord...but other programs can access the internet through it (like MSN).  that seems rather odd to me.   as you can guess my other ethernent cord(my much too short to reach my xbox ethernet cord) is not having any troubles.

so...

why would the cord be having only some internet problems?

and is there something i can do to fix the cord...or do i need a new one? 

Wow, that could be a lot of things. Have you checked your firewall to make sure that port 80 isn't blocked?

no, i havent...but is that likely something that would only affect one cord and not the other?

Oh, I misread the first quote.

The one thing that happened to me while using my DSL was kind of similar to what you are experiencing.

With my DSL connection, I am on the very outer edges of the loop, and I did have a 100-ft. ethernet cable running to my XBOX 360 (I wound up the 80-feet I didn't need, and only used 20-ft. of length).

Anyway, considering my signal strength was so weak to begin with, the fact that I was extending my connection outside of the loop by an additional 100-feet completely killed my connection.

Whenever I moved the modem closer, I ran a 10-foot cable and it connected fine (not fast, but sufficient).

Of course, that wasn't much of a solution, so I ordered cable-internet service, and my speed improved greatly.

I know that doesn't really help you, but that's just what happened to me in similar circumstance. I'd call your provider and have them run a loop test (if you have DSL) and see how far out you are.

is it a cross cord?

i has cable

idk what a cross cord is.  its the ethernet cord that came with my xbox.  big long grey thing.

Then i dont have a clue..

Me either. I exhausted my first guess, and kirby0087 used my second one, so it's really odd.

Last question though, are you running through a router or straight from your cable modem?

i generally go through my modem...but ive got a router here as well atm. (as i had a ps3 hooked up here the other day and they forgot their router lol)

when hooked up through the modem, the xbox was telling me it couldnt get an IP address
when hooked up through the router i think it was saying something about a DNS
when going from modem to PC all it said was that it cant connect to the internet

edit: 

i had it connected both ways just the other day...so this is something from yesterday or today.