this is a really random and dum question.my old modem broke up, so i bought a new one, witch should be wireless and connect wia ethernet. but, what is the wireless part in here? i have a wire going in my comp and to the phone line but witch one should be wireless?
and also, if its the part that cons to computer, do i need to isntall something or what? also if so can i use xbox live wireleslly?

There should be a manual with your new modem. I suggest reading it

As for connecting your Xbox through the wireless, you will need a wireless adapter for the Xbox.

EDIT: your computer will also need to be fitted with some sort of wireless receiver in order to connect to the wireless modem (could be that that came with the new modem, check it). However, I think that you can just as well connect it with a wire if you wish and just not use the wireless option.

Quote from obsolum :

There should be a manual with your new modem. I suggest reading it

As for connecting your Xbox through the wireless, you will need a wireless adapter for the Xbox.

yeh maybe i should, i just plug'n played. didnt really read anything. now i just need to find it...

i have a pc, rather than laptop, so just plug it in, but i can run my PS3 wirelessly straight away, i think there was a code that came with the internet so it knew it's mine, but apart from that i think it was relatively simple.