To show/add developer tab in MS word 2007 ribbon, follow below steps.
1. Click on office button, you will get options like shown in below figure.
2. Click “Word options” at bottom
3. Click Popular button at top-left
4. On right-side, check “Show Developer tab in the ribbon” option
5. Click OK button
Now, you can see Developer tab in the ribbon. From that tab, you can access macro and other tools.