Henry miller wrote: If you want some example source code, search for "diff", which is a unix utility that does what you want. (and many other things) Good idea. However, "diff" is for text files. If you want to compare binary files, try the unix utility "cmp" If you don't have the source to the unix utilities, try looking at cygwin, a Unix-on-DOS implementation: http://www.cygwin.com[^]