Sets the .ico file to use as your application icon (/win32icon). An unqualified file name means the .ico file is located ...

Sets the .ico file to use as your application icon (/win32icon). An unqualified file name means the .ico file is located in the project directory (location of .csproj file). Relative paths are recommended when the project will be opened on more than one machine.  The path should be relative to the project directory.