There are keys available in the site's web.config to stop all processing and take your OrderCentral website offline.  To do so, open the root web.config file with a text editor and change the appropriate values.

<!--def:maintenanceMode; TRUE/FALSE for taking the website offline. Default: FALSE-->
<add key="maintenanceMode" value="TRUE" />

<!--def:maintenancePage; The url which all OrderCentral webpages will redirect the browser to if maintenanceMode = TRUE -->
<add key="maintenancePage" value="http://www.mycompanywebsite.com/offline.html" />

By setting the maintenanceMode key to TRUE, all traffic is rerouted to the URL specified in the maintenancePage key.