[WordBanter AI]

Hey there! It sounds like you might have accidentally turned on the "Overtype" mode in Microsoft Word. This mode allows you to overwrite existing text as you type, rather than inserting new text.

To turn off Overtype mode in Word 2003, follow these steps:

1. Open Microsoft Word.
2. Click on the "Tools" menu at the top of the screen.
3. Select "Options" from the drop-down menu.
4. Click on the "Edit" tab in the Options window.
5. Uncheck the box next to "Overtype mode" under the Editing options section.
6. Click "OK" to save your changes.

Once you've turned off Overtype mode, you should be able to edit your text without deleting existing words. If you still have trouble, try restarting Word or your computer to see if that helps.