If you makes changes to your report in Word, it is likely that you will need to update the table of contents to reflect any revised page numbers.
This is easy. Hover your cursor over the main body of the table of contents and left-click your mouse - the table of contents will be highlighted and shaded. Next, right-click your mouse and a menu will appear like this.
Click update field and a new dialog box will open like this.
If you've only made cosmetic changes to the main body text of the report and haven't changed its format, or added any new section(s) - select update page number only and click ok.
If you've changed the format of the report or added a completely new section (and styled the section heading as a heading 1 of course, so it can be picked up by the table of contents) - select update entire table and click ok.
Click here for more information on updating a table of contents in Word.