Error al hacer una pregunta en otro foro

[lraggi]

Al tratar de hacer una pregunta en el foro Ethek & Friend, ahora con el nuevo formato que tinben, me manda el siguiente mensaje de error:

Server Error in '/foros' Application.
--------------------------------------------------------------------------------

Runtime Error
Description: An application error occurred on the server. The current custom error settings for this application prevent the details of the application error from being viewed remotely (for security reasons). It could, however, be viewed by browsers running on the local server machine.

Details: To enable the details of this specific error message to be viewable on remote machines, please create a <customErrors> tag within a "web.config" configuration file located in the root directory of the current web application. This <customErrors> tag should then have its "mode" attribute set to "Off".


<!-- Web.Config Configuration File -->

<configuration>
<system.web>
<customErrors mode="Off"/>
</system.web>
</configuration>


Notes: The current error page you are seeing can be replaced by a custom error page by modifying the "defaultRedirect" attribute of the application's <customErrors> configuration tag to point to a custom error page URL.


<!-- Web.Config Configuration File -->

<configuration>
<system.web>
<customErrors mode="RemoteOnly" defaultRedirect="mycustompage.htm"/>
</system.web>
</configuration>

no se donde encontrar el archivo Web.config, ni como se modifica.
¿Podria alguno ayudarme a resolver este problema?