note roho The output of perl -V:archname is archname='MSWin32-x86-multi-thread'; so $NTConfiguration is set to true. I deleted $opt{LD} right before WriteMakefile. When I re-ran perl Makefile.PL and nmake I got the following linker errors: <p> <code> link -out:blib\arch\auto\DBD\Informix\Informix.dll -dll -nologo -nodefaultlib -debug -opt:ref,icf -libpath:"C:\Perl\lib\CORE" -machine:x86 Informix.obj dbdimp.obj dbdattr.obj sqltoken.obj sqltype.obj ixblob.obj odbctype.obj kludge.obj link.obj esqlcver.obj esqlc_v6.obj /LIBPATH:C:\PROGRA~2\IBM\Informix\11.70/lib /LIBPATH:C:\PROGRA~2\IBM\Informix\11.70/lib/esql "C:/PROGRA~2/IBM/Informix/11.70\lib\isqlt09a.lib" "C:/PROGRA~2/IBM/Informix/11.70\lib\igl4n304.lib" "C:/PROGRA~2/IBM/Informix/11.70\lib\iglxn304.lib" "C:/PROGRA~2/IBM/Informix/11.70\lib\igo4n304.lib" netapi32.lib wsock32.lib user32.lib winmm.lib advapi32.lib C:\Perl\lib\CORE\perl58.lib oldnames.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib netapi32.lib uuid.lib ws2_32.lib mpr.lib winmm.lib version.lib odbc32.lib odbccp32.lib msvcrt.lib -def:Informix.def Informix.def : error LNK2001: unresolved external symbol ifx_checkAPI Informix.def : error LNK2001: unresolved external symbol ifx_checkAPI blib\arch\auto\DBD\Informix\Informix.lib : fatal error LNK1120: 2 unresolved externals NMAKE : fatal error U1077: '"c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\BIN\link.EXE"' : return code '0x460' Stop. </code> <p> I checked Informix.def and its contents are: <p> <code> LIBRARY "Informix" EXPORTS ifx_checkAPI _ifx_checkAPI = ifx_checkAPI boot_DBD__Informix _boot_DBD__Informix = boot_DBD__Informix </code> <p> I have no idea what this file and its contents are supposed to do. You're right. This is a mess. I would like to clean it up but writing a new Makefile.PL is beyond my expertise. All I want to do is install the module and get on with my work. <div class="pmsig"><div class="pmsig-140424"> <p> "Its not how hard you work, its how much you get done." </div></div> 987922 988143