el problema es el siguiente , mi messenger dejo de trabajarme, lo borre para volverlo a instalar, pero ahora por alguna razon firefox no me deja, disque por problemas de seguridad, la cosa que cuando quiero entrar a la pagina de dawnload de el messenger, me da esta pagina de error, el primer codigo, es el que no me deja bajarlo, debo sustituirlo por el segundo codigo, para poder acceder, pero el problema es que no tengo ni idea de como hacerlo

Server Error in '/' 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>