Summarize:

Open your preferred Internet browser by double-clicking on its icon on your desktop or Start menu. On the address bar at the top of the browser screen, type in www.Twitter.com and hit Enter. You will be taken to Twitter's home page. On the top part of the screen are two boxes. One of the boxes is for entering your email address while the other is used for your password. Click each box respectively and enter in your information. When you are finished, click "Log in" to access your account. Click on the small gear box located on the top-right side of the screen. This will cause a drop-down menu to appear; select "Edit Profile" from the options. " This is right beside your current profile picture in the middle of the Edit Profile screen " A pop-up window will appear showing the pictures currently on your computer. Scroll through your images until you find the one you want to use, and click on it to select it. After you have selected your profile picture, a new window will pop up letting you adjust how your new profile picture is shown. You can click and drag the image around until it fills the colored box to your liking. When you're done, click the blue "Apply" button below your new picture. Your picture will automatically save. When you go back to the initial screen, you should see your new profile picture on your profile.
Launch an Internet browser. Head to Twitter's website. Sign into your Twitter account. Access the Edit Profile menu. Click on "Change photo. Click on "Upload photo. Select an image. Adjust the image. Apply the changes.