When using a Settings.settings file in .NET, where is the config actually stored? I want to delete the saved settings to go back to the default state, but can\'t find where
Assuming that you're talking about desktop and not web applications:
When you add settings to a project, VS creates a file named app.config in your project directory and stores the settings in that file. It also builds the Settings.cs file that provides the static accessors to the individual settings.
At compile time, VS will (by default; you can change this) copy the app.config to the build directory, changing its name to match the executable (e.g. if your executable is named foo.exe, the file will be named foo.exe.config), which is the name the .NET configuration manager looks for when it retrieves settings at runtime.
If you change a setting through the VS settings editor, it will update both app.config and Settings.cs. (If you look at the property accessors in the generated code in Settings.cs, you'll see that they're marked with an attribute containing the default value of the setting that's in your app.config file.) If you change a setting by editing the app.config file directly, Settings.cs won't be updated, but the new value will still be used by your program when you run it, because app.config gets copied to foo.exe.config at compile time. If you turn this off (by setting the file's properties), you can change a setting by directly editing the foo.exe.config file in the build directory.
Then there are user-scoped settings.
Application-scope settings are read-only. Your program can modify and save user-scope settings, thus allowing each user to have his/her own settings. These settings aren't stored in the foo.exe.config file (since under Vista, at least, programs can't write to any subdirectory of Program Files without elevation); they're stored in a configuration file in the user's application data directory.
The path to that file is %appdata%\%publisher_name%\%program_name%\%version%\user.config, e.g. C:\Users\My Name\AppData\Local\My_Company\My_Program.exe\1.0.0\user.config. Note that if you've given your program a strong name, the strong name will be appended to the program name in this path.