Runtime Error -- Custom Pages

To View Real Error Description in SharePoint 2010:

Open the web.config (“C:\inetpub\wwwroot\wss\VirtualDirectories\<port>”) and set:
1. Debug=”true” instead of the default of Debug=”false”
2. CallStack=”true” instead of the default of CallStack=”false”
3. CustomErrors=”Off” instead of the default of CustomErrors=”On”

Open other web.config (C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\TEMPLATE\LAYOUTS\web.config) and set:
1. CustomErrors=”Off”