If you’re using Windows 10 and don’t know how to change the profile account image, here is the right post for you.

The account picture is the image next to your email address when you logon to Windows 10. This image at the logon screen can be picture of yourself or anything you want.
Windows 10 logon screen
Windows 10 logon screen

There is one important thing you need to know before changing your account image: The account picture on your PC is used locally only on your computer, another is the profile image from the Microsoft account. 
If you want to use your Microsoft account profile image as your account image, just link your Microsoft account with your PC, Windows 10 will automatically sync your profile image as account image.
If you don’t want to use Microsoft profile picture, follow these steps below:
1. Open Settings, and click on the Accounts icon and then click Your account.
2. If you want to use an image from your computer, click Browse. Navigate to the photo you want to use and click a photo to select it, then click Choose picture.
3. If you want to take a new picture using the external or inbuilt camera, click Camera. Take a photo and use it.
See below image for demo:
Step by step to change your account picture on Windows 10
Step by step to change your account picture on Windows 10