In Microsoft Word, each page automatically has a one-inch margin. To set 1-inch margins in Microsoft Word, you can follow these steps:

1. Click on the "Page Layout" tab at the top of the screen.
2. Click on the "Margins" option.
3. In the dropdown menu, choose "Custom Margins".
4. Manually set your margins by using the up and down arrows to input "1" in the boxes for Top, Bottom, Left, and Right.
5. Confirm by clicking "OK".

This process will effectively set your document to have 1-inch margins all around. If you want to change the margins to a different size, you can choose from several built-in margin settings or create custom ones.