To add to what Graeme has said, you should never hard code a file path into your app - it requires you to change the app between development and release versions, which means what you release is untested.
Use the Settings file instead - open the Solution Explorer pane, the project branch, the Properties twig, and double click the "Settings.settings" leaf. Add your path to that with the name "LogPath" and you can access it in your code via "
Properties.Settings.Default.LogPath
Now you can change the path outside the app and you don't need to recompile, or provide a mechanism to set the path inside your app options form if you have one.