Checking if your kit is complete...
Looks good
Writing Makefile for Win32API::MIDI

Microsoft (R) Program Maintenance Utility   Version 6.00.8168.0
Copyright (C) Microsoft Corp 1988-1998. All rights reserved.

Math::BigInt: couldn't load specified math lib(s), fallback to Math::BigInt::FastCalc at C:/cpanrun/build/5-10-0/site/lib/Win32API/File.pm line 20
cp MIDI/SysEX/Yamaha.pm blib\lib\Win32API\MIDI\SysEX\Yamaha.pm
cp MIDI/SysEX/Roland.pm blib\lib\Win32API\MIDI\SysEX\Roland.pm
cp MIDI.pm blib\lib\Win32API\MIDI.pm
cp MIDI/Out.pm blib\lib\Win32API\MIDI\Out.pm
cp MIDI/SysEX/MIDIbox.pm blib\lib\Win32API\MIDI\SysEX\MIDIbox.pm
cp MIDI/SysEX.pm blib\lib\Win32API\MIDI\SysEX.pm
	C:\cpanrun\build\5-10-0\bin\perl.exe C:\cpanrun\build\5-10-0\lib\ExtUtils\xsubpp  -typemap C:\cpanrun\build\5-10-0\lib\ExtUtils\typemap -typemap typemap  MIDI.xs > MIDI.xsc && C:\cpanrun\build\5-10-0\bin\perl.exe -MExtUtils::Command -e mv MIDI.xsc MIDI.c
	cl -c    -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=\"0.05\"  -DXS_VERSION=\"0.05\"  "-IC:\cpanrun\build\5-10-0\lib\CORE"   MIDI.c
MIDI.c
MIDI.xs(272) : error C2065: 'DWORD_PTR' : undeclared identifier
MIDI.xs(272) : error C2143: syntax error : missing ')' before 'constant'
MIDI.xs(272) : error C2198: 'midiInOpen' : too few actual parameters
MIDI.xs(294) : error C2146: syntax error : missing ')' before identifier 'midiInProc_wrapper'
MIDI.xs(294) : error C2198: 'midiInOpen' : too few actual parameters
NMAKE : fatal error U1077: 'cl' : return code '0x2'
Stop.