will xbox live lag?

i really wanna get an xbox cuz the wii just makes me mad... my friends have xboxs and cod4 and whenever i go to there house i always play cod4 and it is my favorite game so i got WaW but its just not good at all. anyways when i play cod on the wii it doesnt lag that much but when someone is using a computer in my house the laggets really bad. my friends have a pretty fast internet but mine is not so good. so just wondering if my bro or dad are using their computers while im on xbox live will it start lagging?

lol ok..... well im gonna say maybe, if your connection lags when someones on the computer when your on the wii then it should still lag when your on the xbox

Lag has NOTHING to do with the console. It depends entirely on your location to ISP servers, bandwidth, latency, how many network connected devices your using and for what and many, many other factors. To ask if Xbox Live will lag is like asking somebody who's been inside all day what the weather is like.