Help me please. (about hex stuff)

Well ididnt know where to ask for help about this so i came to this.

Anyways, i am looking for a program that can compare hex tables / binary files, and tell what the difference is.
I need a program for this, because i am comparing a binary file of the memory of a pc game, and then the memory of the same pc game, but modified. i only changed one thing to modify it, so there should only be ONE changed string. please guys help help help me! it is way too much to look thru with my own eyes, because it is a huge file :'(
thanks in advance

halo, u may want to google for it.

For instance, theres a shareware "Hexcmp" thrown out by google search... u may want to chk it out...