I don't know the size of your workbooks, but one solution for comparing two
worksheets is on a third worksheet, write this formula in cell a1 and copy
over the area you need to compare:
=if(Sheet1!a1=Sheet2!a1,"","Different")
This says if cell a1 is the same on both sheet 1 and 2 do nothing (""), if
the cells are not the same it will type the word "Different".
If you have multiple sheets, the areas are extremely large, or the sheets
are not exactly lined up the same, this may be a poor solution. Good luck.