Application Pools Not Starting After Reboot

IIS Manager > Computer Name > Configuration Editor > Section dropdown > system.applicationhost > application pools > (Collection) > eclipses (…) > select application pool > startMode > AlwaysRunning.

Source:
http://msdn.microsoft.com/en-us/library/ee677285%28v=azure.10%29.aspx

SharePoint 2013 - Sign in as a Different User

/_layouts/closeConnection.aspx?loginasanotheruser=true

Reference:
http://blog.credera.com/technology-insights/microsoft-solutions/how-to-sign-in-as-a-different-user-in-sharepoint-2013/