所有都准备好后，地址栏输入：http://localhost/install/index.aspx后显示如下，高手帮忙看看怎么回事？
Server Application Unavailable
The web application you are attempting to access on this web server is currently unavailable. Please hit the "Refresh" button in your web browser to retry your request.
Administrator Note: An error message detailing the cause of this specific request failure can be found in the application event log of the web server. Please review this log entry to discover what caused this error to occur.
