How to Remove a web.config Modification Using PowerShell

Next, list all of the SPWebConfigModification objects that have been applied to the Web application. These objects are stored in the WebConfigModifications property of the Web application.

 1: $webApp = Get-SPWebApplication WebApplicationURL
 2: $webApp.WebConfigModifications

In this example, you can see some of the modifications added by Bamboo products to support Telerik:

Now, we can identify a particular modification and remove it using the commands shown below.

 1: $config = $webApp.WebConfigModifications | Where-Object {condition_to_identify_the_object}
 2: $webApp.WebConfigModifications.Remove($config)
 3: $webApp.Update()
 4: $webApp.Parent.ApplyWebConfigModifications()

In this example, we’ll remove the modification with the name “add[@name=[‘Session’]” and path “configuration/system.webServer/Modules”.

The ApplyWebConfigModifications() method applies this change across the farm for the specific web application, so we don’t need to worry about each physical web.config file at the server-level. That is one of the main advantages of using PowerShell to update web.config modifications.

If there are multiple modifications we need to remove, we can use a loop to do that. The following example removes all of the modifications added by Bamboo Telerik Config in a particular Web application (they all have the same Owner value):

 1: $BambooConfigs = $webApp.WebConfigModifications | 
    Where-Object {$_.Owner -eq "Bamboo.SP2010.Config"}
 2: foreach ($config in $BambooConfigs) {
 3:     $webApp.WebConfigModifications.Remove($config)
 4: }
 5: $webApp.Update()
 6: $webApp.Parent.ApplyWebConfigModifications()