Question: How can I permanently change the contents of the command prompt under Windows 7? I know about the `prompt` command, and the [content options](http://www.computerhope.com/prompthl.htm#03), but I'm not sure where to save the custom prompt so that it's used every time. Old web pages say `autoexec.bat`, but that seems to be an uneditable dummy file under 7.

Answer: 
Use the User Environment variables.

Right Click Computer --> Properties --> Advanced Settings --> Advanced --> Environment Variables

In the User variables box click "New..".

Name the variable "Prompt" (without quotes), and set it's value to what you want the prompt to be (refer to "prompt /?" at a command line).

OK --> OK

Open a command prompt (cmd) and it should use that prompt.

Tested in Windows 7, and it still works like it did in NT 4 :)

Hope that helps...
I found some instructions here: <http://www.wikihow.com/Create-a-Custom-Windows-Command-Prompt> 
and here: <http://windowsxp.mvps.org/autoruncmd.htm> that let you customize your command prompt. 
Evidently there are several registry keys that let you modify the default behavior of cmd.