If you are using a mailbox from the "Rambler", to change his name (login), you can not. Exit here only one: register address a new email. If you need to then change the password, you will need to log in to the box itself, go to the menu called "Settings", choose "Change password", enter new, confirm it, and in the end save the changes.
To change your existing login ID (i.e. address) is not on Yandex. To create a new box need to register to Yandex-mail (please fill in the form). By the way, any mail servers have the ability to create an unlimited number of boxes. And so you do not have to create a new, invent it a nice and catchy name right.
In the service mail.ru after you register you also cannot change your username; you can only create a new box(with a new username and password) and delete the old (if it is no longer needed). Register a new box is on the website http://e.mail.ru/cgi-bin/signup; and removal on http://win.mail.ru/cgi-bin/delete.
To send and receive electronic messages and in the email agent "Windows Mail". To create/remove your account, start the application itself (open the start menu, select All programs and then click on the heading "Windows Mail". As soon as you see a menu called "Tools", click on the account, if it is already registered, and Add, if you use this agent for the first time. Next, you will need to follow the instructions.