<-----------snip------------> # version 1 - succeeds my $si = pack( "L17", ((0) x 17) ); $si = pack( "LL16", length( $si ), ((0) x 16 ) ); my $pi = pack( "L4", ((0) x 4 ) ); # version 2 - fails my $si = Win32::API::Struct->new( "STARTUPINFO" ); $si->{cb} = $si->sizeof(); my $pi = Win32::API::Struct->new( "PROCESS_INFORMATION" ); my $retval = CreateProcess( "c:\\winnt\\notepad.exe", 0, # unused - cmdline ptr, unused 0, # unused - proc attributes ptr 0, # unused - thread attributes ptr 0, # unused - inherit handles 0, # unused - creation flags 0, # unused - env pointer 0, # unused - current dir ptr $si, $pi ); <-----------snip------------>