The only way to get infections like not going on live is to have a friend go to his house spend the night and do system link thats what i do all the time....(Im the one with the jtag)
yes there is...
but first you have to clear the system cache of your xbox. Then unplug the power cable from your 360 during it downloads the update. do this steps twice. then after the third time downloading go into a ranked match and pull out your hdd/MU. when it restards just pull the power again. when it says pull MU back in then just put back in and remove power then.
let it unpluged for bout 20 secs.
the take your MU/HDD and open up modio and do the campaign mods(any you want). then unplug the MU and start your xbox(MU unplugged!!) launch mw2 and go to multiplayer then it says you have to sign in with account. pull power again and then put MU in. start xbox. then go to multiplayer of mw2 and do the update. here is the tricky part... you have to pull out the MU exactly when the update is half way done. and put it back in fast. restart xbox by putting out the AV cable.
then just go to private match and your mods will be there everytime you have the modded MU plugged in!!!
follow all this steps correctly or it wont work!