If you have WORD and your files are text files, create two documents in respect of each file: he first contains the 'source' and the second the 'target'

Open either the 'source' or the 'target' in WORD and then use : Tools | Track Changes |Compare Documents. This will alter the document you have open (so don't save it or you'll overwrite the original). The active document has vertical bars in the left margin wherever there are differences. Text which has been struck through indicates text that has been removed; text that is underlined shows new text. The comparison is text sensitive.