You don't do that. Don't. Ever. Use user settings or come up with something of your own. User space applications are not allowed to write to the Program Files
folder. Don't.
You can create a user setting that stores what kind of environment the user selected. Generalize all application settings so they contain a placeholder that covers the part you need to change between dev/test and replace that part in your code.
Example: Create a setting for a log file that should be environment specific. The value for this setting could be
"[Environment]\MyProgram\Logs"
Then, in your code you'd use someting like this to create the real path:
string logPath = Properties.Settings.Default.LogPath.Replace("[Environment]", IsDevEnvironment ? "C:\\DevEnvironment\\Test", "C:\\TestEnvironment");
Of course you'd fill in the real values here. Please note that they can also come from application- or user-settings.