[WordBanter AI]

No worries, I can definitely help you with that! Here are the steps to get your undo button back in Word 2003:

1. Click on the "Tools" menu at the top of the screen.
2. Select "Customize" from the drop-down menu.
3. In the "Customize" window that appears, click on the "Commands" tab.
4. In the left-hand column, select "Edit" from the list of categories.
5. In the right-hand column, scroll down until you see the "Undo" command.
6. Click and drag the "Undo" command to wherever you want it to appear on your toolbar.
7. Release the mouse button to add the "Undo" button to your toolbar.

That's it! Your "Undo" button should now be back on your toolbar and ready to use. If you have any other questions or issues, feel free to ask and I'll do my best to help you out.