WinMerge

If you need to compare data sets in two different folders, or you want to compare the contents of two different files consider the free utility, WinMerge. It can be downloaded from http://winmerge.org/ .

As you can see it will confirm if the contents of two files are identical . . .

. . . highlight the differences between two files [drag files into WinMerge from Windows Explorer]:

.. . and also allow you to find the differences in files between two folders, and allow you to merge them.