Keep user’s settings after altering assembly/file version

Use the built in Settings classes, you just need to upgrade the settings anytime you change the application version. Here’s how to do it:
In the Settings.settings file, create a new setting
UpdateSettings type=bool Scope=User Value=True

Include the following code before you use any Settings (it can run every time the app runs, as this makes running in debugger easier too)

// Copy user settings from previous application version if necessary
if (MyApp.Properties.Settings.Default.UpdateSettings)
{
    MyApp.Properties.Settings.Default.Upgrade();
    MyApp.Properties.Settings.Default.UpdateSettings = false;
    MyApp.Properties.Settings.Default.Save();
}

When your new application version is run UpdateSettings will have a default value of True and none of your old settings will be used. If UpdateSettings is true we upgrade the settings from the old settings and save then under the new app version.