How do I ensure email security by password on both my laptop and desktop?

My laptop and desktop are connected to BT wireless hub. when I sign on to my laptop in order to acces my email i have to enter my email address and password. However when I sign on to my desktop i can get into email without entering any details about address or password and i want to protect my desktop in the same way as my laptop is protected.|||You could use avg free. That is a security and anti virus program. The link below