Checking if your kit is complete... Looks good you are using MSVC... my condolences. at Makefile.PL line 54. you are using MSVC... my condolences. at Makefile.PL line 54. Writing Makefile for Wifi::WpaCtrl Microsoft (R) Program Maintenance Utility Version 6.00.8168.0 Copyright (C) Microsoft Corp 1988-1998. All rights reserved. cp pm/WpaCtrl.pm blib\lib\Wifi/WpaCtrl.pm C:\cpanrun\build\5-10-0\bin\perl.exe C:\cpanrun\build\5-10-0\lib\ExtUtils\xsubpp -noprototypes -typemap C:\cpanrun\build\5-10-0\lib\ExtUtils\typemap xs/WpaCtrl.xs > xs/WpaCtrl.xsc && C:\cpanrun\build\5-10-0\bin\perl.exe -MExtUtils::Command -e mv xs/WpaCtrl.xsc xs/WpaCtrl.c cl -c -Wall -Iwpa_ctrl -Iperl_glue -nologo -GF -W3 -MD -Zi -DNDEBUG -O1 -DWIN32 -D_CONSOLE -DNO_STRICT -DHAVE_DES_FCRYPT -DUSE_SITECUSTOMIZE -DPRIVLIB_LAST_IN_INC -DPERL_IMPLICIT_CONTEXT -DPERL_IMPLICIT_SYS -DUSE_PERLIO -DPERL_MSVCRT_READFIX -MD -Zi -DNDEBUG -O1 -DVERSION=\"0.02\" -DXS_VERSION=\"0.02\" /Foxs/WpaCtrl.obj "-IC:\cpanrun\build\5-10-0\lib\CORE" xs/WpaCtrl.c Command line error D2021 : invalid numeric argument '/Wall' NMAKE : fatal error U1077: 'cl' : return code '0x2' Stop.