1) Open the word document in Office 2010, Click the Review tab and choose Compare -> Compare.
The Compare Documents dialog box shows up.
2) Select the original document from the Original Document drop-down list.
If you can’t find the original document, click the wee folder icon to browse for it.
3) Select the edited document from the Revised Document drop-down list.
Like with the original document, you can locate the revised one by clicking the folder icon to browse.
4) Click OK.
Word compares the two documents and notes all changes. Then it displays a list of changes, the compared document with changes marked, plus the original and revised documents.
5) If your screen doesn’t display all the information it should, click the Compare button again and, from its menu, choose Show Source Documents -> Show Both.
Look it over! Peruse the changes made to your pristine prose by the barbarian interlopers; use the Reviewing pane to witness each change individually.
6) Click a change in the Reviewing pane if you want to see which part of your document was folded, spindled, or mutilated.
Each reviewer is given his or her own color on your screen. For example, the writer’s revision marks may appear in red, but had a second person reviewed the text, those comments would appear in a second color, and so on for other reviewers.