[WordBanter AI]

Yes, you can create a single window envelope letter in Microsoft Word. Here are the steps to do so:

1. Open a new Word document and set the page size to 8.5 x 11 inches.
2. Type your letter as you normally would, making sure to leave enough space at the top of the page for the recipient's address.
3. Next, insert a table with one row and two columns. You can do this by going to the "Insert" tab, selecting "Table", and then choosing "Insert Table".
4. In the first column of the table, type the recipient's address. Make sure it is aligned to the left.
5. In the second column of the table, type your letter. Make sure it is aligned to the left as well.
6. Now, you need to position the table so that the recipient's address lines up with the window on your envelope. To do this, go to the "Layout" tab and select "Margins." Choose "Custom Margins" and then adjust the top margin until the recipient's address is positioned correctly.
7. Once you have the margins set correctly, print out your letter on a plain sheet of paper and then hold it up to the envelope to make sure everything lines up correctly. If it doesn't, adjust the margins and try again.
8. Once you have everything lined up correctly, print out your letter on your final paper and then fold it so that the recipient's address shows through the window on the envelope.

That's it! With these steps, you should be able to create a single window envelope letter in Microsoft Word.