I have run the makefile.pl but hadn't run the test and the install. here is the command and part of the reaction: perl install.pl ... Installing C:\Perl\site\lib\Win32\API.pm Skipping C:\Perl\site\lib\Win32API\CommPort.pm (unchanged) Installing C:\Perl\site\lib\Win32API\API.pm Writing C:\Perl\site\lib/auto/Win32/SerialPort/.packlist ... Now that I did so, I still get the 'shout': Can't locate loadable object for module Win32::API in @INC (@INC contains: . .\t .\lib ..\lib C:\Perl\site\lib\Win32 C:\Perl\site\lib\Win32API C:/Perl/lib C:/Perl/site/lib) at ..\lib/Win32API/CommPort.pm line 5 Pay attention that the perl, fing the FILE, it has a problem with the object! Do you have any ide how to solve this problem.