Hi Orley, 1. Please make sure you can build any simple application using (just) isalnum(). 2. After step #1 is ok, then start over with pjsip (or just pjlib first), try to stick with http://www.pjsip.org/using.htm#using on every small things. Moreover, please see inline comment... 2008/6/12 G Orley <geo.orley at gmail.com>: ... > in VS 2008 (VC++ 2008) Project - Properties (Alt+F7) - Configuration > Properties - C/C++ - > General - "Additional Include Directories" I've added the following: > (which made a major > improvement in getting as far as I have) > > C:\Documents and Settings\User\My > Documents\Xxxxxx\XXXX_XXX_XXX\pjproject-0.8.0\pjsip\include > C:\Documents and Settings\User\My > Documents\Xxxxxx\XXXX_XXX_XXX\pjproject-0.8.0\pjsip\lib > C:\Documents and Settings\User\My > Documents\Xxxxxx\XXXX_XXX_XXX\pjproject-0.8.0\pjmedia\include > C:\Documents and Settings\User\My > Documents\Xxxxxx\XXXX_XXX_XXX\pjproject-0.8.0\pjmedia\lib > C:\Documents and Settings\User\My > Documents\Xxxxxx\XXXX_XXX_XXX\pjproject-0.8.0\pjlib-util\include > C:\Documents and Settings\User\My > Documents\Xxxxxx\XXXX_XXX_XXX\pjproject-0.8.0\pjlib-util\lib > C:\Documents and Settings\User\My > Documents\Xxxxxx\XXXX_XXX_XXX\pjproject-0.8.0\pjlib\include > C:\Documents and Settings\User\My > Documents\Xxxxxx\XXXX_XXX_XXX\pjproject-0.8.0\pjlib\lib > C:\Documents and Settings\User\My > Documents\Xxxxxx\XXXX_XXX_XXX\pjproject-0.8.0\pjlib\include\pj .... Try to remove the last entry "pjlib\include\pj" (and also the path ending with '..\lib'). Good luck! Regards, nanang