Comparing two worksheets and identifying differences

Hello all! I desperately need some direction. I have a database of information that is changed monthly and given in an excel spreadsheet. I must compare the old and new worksheets to determine what was added, deleted or changed each month. There are roughly 2000 rows and 27 columns to compare. I am looking for a way to identify what the changes are without spending a solid week comparing side by side. I have attached a copy of 2 different months for reference. Any help would be greatly appreciated!! sample 6-20-12.xls sample 7-23-12.xls.

Arlette, Yes, Ideally all 27. I could narrow it down to 12 or so if I had to.

It could be an independent file. A prompt would be awesome!