Windows Live Hotmail is a popular Web-based free e-mail service. Hotmail offers 500GB of storage, a 25MB file size limit for e-mail attachments and can retrieve and send e-mail from other e-mail addresses you may own -- all for free. Hotmail funds the free service through advertisements. An ad appears on the right side of the screen while you are looking at any folders or at any archived message. If you want to remove the side ad, you can do so, but only temporarily.
Scroll down the page until the bottom of the side ad shows.
Click on the words "Close Ad" directly below the advertisement. The side ad disappears, and the rest of the screen expands to the right.
Navigate to a new folder or message or refresh the page, and repeat the process to delete the side ad again.
To remove advertisements permanently, you can upgrade to Hotmail Plus. One of its benefits is no advertisements, but it does carry an annual fee.