If he can't run vanilla, then CF will also not work. If I remember it right, there is on vanilla start some license agreement window or something like this. I'm unsure about this, it's quite long time when I installed vanilla.
Just in case he have something like Norton ... ... look into FAQ, there is guide how to set this particular AV bcs we had confirmed that disabling is not enough, it was still able mess with game files and stopped only after exceptions were set correctly.