What does "For Microsoft Visual C++, run in the Platform SDK command shell" mean?
What's "Platform SDK command shell"? I installed "Platform SDK" for some other reason in my computer but I can't find any command shell, any program called "shell" or "command" or "cmd" or similar. No program I could find kept any window open where I could type some command.
I also have "Visual C++ 9.0 Express Edition". Is it ok? scons says it isn't:

scons withMSVC=1 custom=custom-msvc.py useDouble=1
scons: Reading SConscript files ...

C S O U N D 5

SCons build file for Csound 5:
API library, plugin opcodes, utilities, and front ends.

By Michael Gogins <gogins at pipeline dot com>

For custom options, run 'scons -h'.
For default options, run 'scons -H'.
If headers or libraries are not found, edit 'custom.py'..
For Linux, run in the standard shell
    with standard Python and just run 'scons'.
For MinGW, run in the MSys shell
    and use www.python.org WIN32 Python to run scons.
For Microsoft Visual C++, run in the Platform SDK
    command shell, and use www.python..org WIN32 Python to run scons.

System platform is 'win32'.
Importing complete environment for Microsoft Visual C++ (MSVC)...
Using options from 'custom-msvc.py.'
Build platform is Microsoft Visual C++ (MSVC).
SCons tools on this platform:  ['default', 'mslink', 'msvc', 'g77', 'masm', 'mslib', 'zip']
Using Istvan localisation
CONFIGURATION DECISION: Using double-precision floating point for audio samples.

Checking for C header file stdio.h... no
 *** Failed to compile a simple test program. The compiler is
 *** possibly not set up correctly, or is used with invalid flags.
 *** Check config.log to find out more about the error.

Thanks!