I've seen a lot of posts recently suggesting that ISO modding possibilities could be limitless if you address it the right way. Well i hate to ruin it but those posts couldn't be more wrong. Let me explain why. Now a days when a game company makes a game for the xbox 360 they add file checks to the xex. These file checks are very similar to the .map checks introduced in halo 3. This means if we mod the files on the disk the xex will see those files as tampered with and won't load them. Well this is a simple problem with a not so simple solution. To bypass this issue you can simply modify the xex to not run these file checks, but now a similar system that is built into the xbox firmware sees that the xex you are trying to run is modified and therefor won't run it. This is where jtags come in. Jtags use a time attack to break the so called "chain of trust" that the xboxs rely on to stay secure. Once this chain is broken the console can boot to a modified dash and no longer discriminate against unsigned code. So now hurray! We can run the modified game content now! Then Microsoft gets mad because we messed with their security. So, they find a way to block jtags from live. Some people think its no big deal, I mean we can just mod the files, burn them to a disk, and play them on a flashed xbox. Well guess what, now you've broken the signature on the files and Mr.xex doesn't like that very much. So Mr.xex decides he doesn't want to run those unsigned files and your whole plan falls to pieces.

Basically what I'm trying to say is you can't iso mod games with xex checks involved. This includes Mw2, Black Ops, Halo 3, Halo: REACH, and a large number of other games. I guarantee if you try and iso mod these games you will end up with a wasted double layer disk and a lot of frustration. So don't try, just give that theory up. If you really want to host lobbies again remember: Save the Jtags. Save the world.

Edit: Also something else important. DEV KITS CANNOT SIGN CODE! I don't care how expensive they are they aren't that special. Dev kits were designed to TEST games not MOD them. Sure you can change a lot with dev kits but the same rule still holds. You change the game files, you break the signature. End of story.