That registry hack seems like a Bad Idea(TM) to me.

Much safer is to locate each shortcut you use to launch the command prompt, and adjust its Start In property to suit your needs.  It is also possible to set the command line in the shortcut (edit the Target property) to something like <tt>CMD /K PRESETS.BAT</tt> to process PRESETS.BAT (provide a fully-qualified name for that, of course, and be careful to quote paths with spaces) before landing at an interactive prompt. Again, set the Start In as needed, or put a CD command in the PRESETS.BAT.

I often use this technique to describe command prompts with environment variables as needed for various cross-development tool chains which otherwise would require conflicting definitions for environment variables like INCLUDE and friends. The Microsoft Visual Studio installer sets up something similar, as well as the Windows Device Driver Kit.