When you create your Hotmail account, Microsoft will display a default profile photo, which appears in the top right corner of the page. This tutorial shows you how to change it to your own image.
Change your picture on Hotmail (Outlook.com)
STEP 1: Log in to hotmail account. Then click on your username (top right) and choose “Edit Profile” from the dropdown menu.
STEP 2: Click Profile.
STEP 3: Click Change picture.
STEP 4: Choose file in your computer. After the download finished, then click Save.