If I start a new CMD shell from an existing shell, the new shell inherits the existing environment. Is there a way to start a new shell but have it initialized to the system defaults and not inherit?

Current result:

```
B:\>set _test=blooharky

B:\>cmd
Microsoft Windows [Version 6.1.7600]
Copyright (c) 2009 Microsoft Corporation.  All rights reserved.

B:\>set _
_test=blooharky

```

Desired result:

```
B:\>set _test=blooharky

B:\>cmd /env=default
Microsoft Windows [Version 6.1.7600]
Copyright (c) 2009 Microsoft Corporation.  All rights reserved.

B:\>set _
Environment variable _ not defined

```

**[update]** Solution for this is `start /i cmd`, as shared by dbenham, [below](https://stackoverflow.com/q/8263016/14420). However it doesn't help in the situation where the current shell is already second generation. Example:

```
d:\>set _
Environment variable _ not defined

d:\>set _test=blooharky

d:\>cmd /k

:: some work done using _test here...
:: ...but after we need a new clean shell:

d:\>start /i cmd

d:\>set _
_test=blooharky

:: uhoh, our shell isn't clean!

```