A user took note of an odd issue when a windows security login window appeared. The fact that the window came up asking for credentials isn't a problem and was easily remedied. However, the username that automatically came up is a bit strange. Instead of the user's domain username, there was a string of random characters. I have attached an image of the issue. I would appreciate any information someone can provide on why this happened and how to keep it from happening again. The user is running windows 7 x32, office 2013.