How to show in word Heading4 in the table of contents

By default, Word includes only the top three levels in a table of contents.

To see more headings, you can manually edit the TOC field code.

1. Press Alt+F9 to display field codes. You should see something similar to this: { TOC \o "1-3" \h } on the table of contents
2. Type 4 instead of 3 
3. Press Alt+F9 to hide the field codes 
4. Press F9 to update the TOC