Modding Hard Drive - How Likely To Get Banned, if you mod some game settings what are the dos/don'ts Options

[xboxdawg]

My friend wants to do some halo 3 mods. Just some things to use in private custom matches.

He has a 360 with LT 1.1.

How likely are hard drive mods to cause a ban from Live. I know one friend modded his Red Dead Redemption files to unlock things and also borderlands and messed around with COD WaW zombies plus he was doing the gamertag mod in MW2. He ended up getting his 360 banned.

So my question is what are the do's and don'ts?

Will they ban you for just changing game settings on the HD or did the other things get him banned. Any ideas?

Thanks,

XBD