Checking if your kit is complete... Looks good Writing Makefile for Win32::PerfCounter cp PerfCounter.pm blib/lib/Win32/PerfCounter.pm /home/cpanrun/pa-risc1.1/build/5.8.2/bin/perl /home/cpanrun/pa-risc1.1/build/5.8.2/lib/5.8.2/ExtUtils/xsubpp -typemap /home/cpanrun/pa-risc1.1/build/5.8.2/lib/5.8.2/ExtUtils/typemap PerfCounter.xs > PerfCounter.xsc && mv PerfCounter.xsc PerfCounter.c Please specify prototyping behavior for PerfCounter.xs (see perlxs manual) cc -c -I. -D_POSIX_C_SOURCE=199506L -D_REENTRANT -Ae -D_HPUX_SOURCE -Wl,+vnocompatwarnings -DNO_HASH_SEED -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -fast +Onolimit +Opromote_indirect_calls +DAportable +DS2.0 -DVERSION=\"0.02\" -DXS_VERSION=\"0.02\" +Z "-I/home/cpanrun/pa-risc1.1/build/5.8.2/lib/5.8.2/PA-RISC1.1-thread-multi/CORE" PerfCounter.c cpp: "PerfCounter.xs", line 5: error 4036: Can't open include file 'windows.h'. make: *** [PerfCounter.o] Error 1