Here's a real simple solution to the problem of multiple configurations at
boot up. Being a simple solution, it's not very powerful, but it should
be helpful to someone. It prompts the user for an errorlevel to set. If
none is given in 2 seconds, it times out and sets the errorlevel to zero.

You would put it in your autoexec and then test for the errorlevel and
branch to whatever setup you want, like this:

rem Autoexec.bat
@echo off
prompt $p$g
path=c:\;c:\dos;..

setexec
if errorlevel 9 goto LOAD_W3
if errorlevel 8 goto LOAD_ACAD
if errorlevel 7 goto LOAD_PMENU

...

:END

Come to think of it, this utility is no more than a glorified GETKEY
(a fairly classic debug-script file that gets a key and sets an errorlevel
(exit code) based on the ascii value of the key). Oh well, at least it's
got a timeout. The idea behind the code is one I've been using a lot
lately: query the PC (vidtype.c, included) or the user for an a piece
of information (the video card, a menu choice) and set an errorlevel. Use
a batch file to employ the errorlevel as a decision-maker.

The good thing about this idea is it is LANGUAGE INDEPENDENT. All PC
programming languages (I think) have an equivalent of C's exit() function
(e.g., GODOS() in CLARION).