Windows authentication and pop up window

My application is using Windows authentication. I have set authentication type to Windows and Impersonation to true. When i access the site locally it is working fine. But when i access the site from a different machine in the same network i am getting a pop up window asking me to enter the credentials. Even if i enter my domain username and password it is not accepting and will keep coming up.
Any idea?
 
Thanks in Advance!!
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