How to Sign in Different Mail ID in Same Computer

If you or someone else have already set up a Yahoo Mail account, you can open your Yahoo mailbox.
The process just takes a moment.

Open your Web browser and type "mail.yahoo.com" (without the quotes) in the browser's address bar, then press "Enter."

Type your Yahoo ID. It is the same as the front half of your email address.
For example, if your email address is "[email protected]" enter "jbob" (without the quotes.)

Click the box labeled "Password" and type your Yahoo ID password.
Click the "Sign In" button.

Click "Inbox" to open your Yahoo mailbox.

yahoo mail homepage
http://mail.yahoo.com/

Open Your Yahoo Mailbox
Yahoo Mail is an Internet-based email service that you can check from anywhere in the world where there is Internet access.
If you or someone else have already set up a Yahoo Mail account, you can open your Yahoo mailbox. The process just takes a moment.

Open your Web browser and type "mail.yahoo.com" (without the quotes) in the browser's address bar, then press "Enter."
Type your Yahoo ID. It is the same as the front half of your email address.
For example, if your email address is "[email protected]" enter "jbob" (without the quotes.)

Click the box labeled "Password" and type your Yahoo ID password.
Click the "Sign In" button.
Click "Inbox" to open your Yahoo mailbox.

yahoo mail homepage
http://mail.yahoo.com/

Yahoo Mail is an Internet-based email service that you can check from anywhere in the world where there is Internet access.
If you or someone else have already set up a Yahoo Mail account, you can open your Yahoo mailbox. The process just takes a moment.

Open your Web browser and type "mail.yahoo.com" (without the quotes) in the browser's address bar, then press "Enter."
Type your Yahoo ID. It is the same as the front half of your email address.
For example, if your email address is "[email protected]" enter "jbob" (without the quotes.)


Click the box labeled "Password" and type your Yahoo ID password.
Click the "Sign In" button.

Click "Inbox" to open your Yahoo mailbox.

yahoo mail homepage
http://mail.yahoo.com/

sir its not about the internet explorer
your network card / wireless wi fi is containing what called(physical address ) it differ
from ( ip address) thats how yahoo mail server knows you are on the same computer and then prohibiting you from login tow accounts at the same time and yahoo do this for the safety of information because if your computer is hacked you might loose the both account
there is a solution for your problem if you insets to break securing rules
use Microsoft virtual machine program witch will simulate another PC with another address on your basic computer
but my advice is to keep safety rules

simply use your address and password. Sometimes there is a box on the sign in screen that says sign in as different user. Either way you can still sign in.
Hope it helps