Upgrading an old project to VS2005 (ugh), I ran into this compile warning:
System.Configuration.ConfigurationSettings.AppSettings’ is obsolete: ‘This method is obsolete, it has been replaced by System.Configuration!System.Configuration.ConfigurationManager.AppSettings’
To fix this, do three things. One, add a reference to System.Configuration to your project. Right click on references, add, .Net, pick System.Configuration. There is a bug here; it will show up in the list of references as System.configuration.
Next step: Add a Using System.Configuration; to your file.
Last step: Update the references from ConfigurationSettings.AppSettings to ConfigurationManager.AppSettings and you’re gtg.
Hopefully we’ll upgrade to VS2008 sometime in 2010.