I received a question for a blog reader the other day complaining that they could not find the <machineKey> element in their Machine level web.config or their machine.config file. It was quite puzzling to them and thought that someone may have removed it.

Well, they were right and wrong. Someone did remove it, but that someone was Microsoft.

When .Net 2.0 came out, they did some "reconfiguring" of the config files. The first thing you will notice is that they moved most of the items that developers may want to change to a "Machine-Level" web.config file which can be found right alongside the machine.config file in the C:\WINDOWS\Microsoft.NET\Framework\v2.x\CONFIG folder. The second thing they did was remove elements from the machine.config file that were set at their default level. So if you don't want to change the machineKey, it will be set like the following.

You can find these settings in the web.config.comments file in the same directory.

You can of course override the defaults by adding the element to the machine.config, machine-level web.config, or a web.config in your application.

Happy programming

Doc