Files with the APPREF-MS extension are used in Windows systems. They are a type of shortcut with which you can install client applications directly from the Internet. They contain the URL of the program to be installed. This operation is performed using a technology developed by Microsoft called ClicOnce.

Applications installed with APPREF-MS files are built on the basis of the Microsoft .NET Framework. The installation process itself does not require administrator privileges in the system, because it is loaded only in the context of an active user.