Kerberos authentication in custom webpart

I developed a custom sandbox webpart which queries a single video file and loads it in a page.

The issue that I'm facing now is that Internet Explorer, Firefox and Google Chrome browsers raises the window which ask about Kerberos authentication when the webpart gets videos with .wmv extension.

This situation is not happening with other extensions like .mp4 and .ogg.

During testing and in production enviroment, I checked the Save password Checked, but even when the SharePoint user login in his account, the windows about Kerberos authentication appears after close the browser.

While the customers use mostly Internet Explorer and may have some videos with .wmv extension, my conern is: how to disable the Kerberos authentication window or what approach can be done in this situation?

N.B: I haven't knowledges about SharePoint or Kerberos configuration.