Xbox Live--help me plz

I'm having a lot of trouble with connecting to xbox live. i was using a network bridge but that wasn't really working out for me, i could connect but in order to connect i had to plug in my Ethernet cable to my xbox and laptop, try connecting to xbox live and fail, restart my laptop, and continuously restart the xbox live connectivity test until it finally connected but even then the connection seemed slow and lagged. i have comcast cable internet and a very fast brand new windows 7 laptop so i know my connection is fast. I've tried the whole "click on properties and click the sharing tab and check the boxes, etc. etc." but the problem with that is i have no sharing tab, and if i do it through the local connection my internet stops working. we have a wireless router that 3 laptops connect to wirelessly, a desktop and an xbox that connect through wires. in my room i have a laptop and an xbox, my laptop connects wirelessly. our network is password protected and I'm not the one able to make changes to the network so i have only my specific laptop to work with and change settings to. if anybody could possibly help me i would appreciate it to no end, i miss being able to play my xbox live and being able to sign directly in without restarting a bunch of stuff and spending 15 minutes trying to connect. thanks!

i have bridged the connection, and, it did work as far as being able to get on xbox live, but the quality was poor, my gaming was lagged and the connecting process was complicated. i couldn't just switch my console on and log on automatically i had to restart my laptop several times and continuously test the connection on my xbox.

well ik its windows 7 based if that's what u mean, idk if that's windows 7 starter or not but yeah, i'm not good with computers