If your ASP.NET site receives the following error message:
Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.
Parser Error Message: It is an error to use a section registered as allowDefinition='MachineToApplication' beyond application level. This error can be caused by a virtual directory not being configured as an application in IIS.
If your site is running off a sub folder like(http://www.domain.com/application/), then it's very likely that your sub folder is not an asp.net application. To fix this, you can login to your myASP.NET control panel-> ASP.NET Manager and set your sub folder as an application.