Question: Below is the error message when I run "scons" to compiler in windows7:

```
-----------------------------------------------------------------------------------
'cl' is not recognized as an internal or external command,
operable program or batch file.
scons: *** [out\windows-x86-MD-unicode-vs2008-rel\obj-static\src\featuresets\ada                                      pters\im-history\AddToChatRoomHistoryVisitor.obj] Error 1
scons: building terminated because of errors.
-----------------------------------------------------------------------------------

```

I have added path to environment variables already, but still met this problem.

Below is the PATH info of environment variables:

```
--------------------------------------------------------------------------------------------
PATH=C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v
1.0\;C:\Program Files\CREDANT\Shield v7.1\;C:\Program Files (x86)\QuickTime\QTSystem\;C:\Program Fil
es\Microsoft SQL Server\110\Tools\Binn\;C:\Program Files\TortoiseSVN\bin;C:\Python27;C:\cygwin64\bin
;C:\Python27\scons-2.3.1;c:\Program Files (x86)\Microsoft SQL Server\100\Tools\Binn\;c:\Program File
s\Microsoft SQL Server\100\Tools\Binn\;c:\Program Files\Microsoft SQL Server\100\DTS\Binn\;C:\Progra
m Files (x86)\Microsoft Visual Studio 10.0\VC\bin;C:\Python27\Scripts;C:\Program Files (x86)\Microso
ft Visual Studio 10.0\VC\lib;C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\include
--------------------------------------------------------------------------------------------

```

Answer: 
SCons has logic to find the location of the visual studio install and set the path and other environment variables needed by visual studio tools by inspecting the registry and also default install locations.

If it's failing for you then you should produce a debug log and pastebin it somewhere for us to see.

use:

```
set SCONS_MSCOMMON_DEBUG=%TEMP%\SCONS_MSVS_DEBUG.log

```

and then runs scons from the same shell. The log will be in 

> 
> %TEMP%\SCONS\_MSVS\_DEBUG.log
> 
> 
> 

You might also try the latest version of SCons 2.4.1 as I note there were some fixes for MSVS/MSVC in later versions. But in theory 2.3.1 should find Visual Studio 2010..
Simply do window search for cl.exe, and add that path to PATH variable, save it. Close the existing open command and reopen it it before executing cl.exe. Hope this will work.