Windows has no signals. Perl offers a minimal signal emulation that has its own problems. See also Re: Handling killing the perl process and Re: Signals in Strawberry Perl: Name or number?.

Windows also has no fork() and no exec() API. Recent perl versions offer a more or less fragile emulation based on interpreter threads. In other words: Perl fakes several forked processes of the same script in a single Windows process.

Using both emulations plus threads is just begging for trouble.

Don't use signals, don't use fork(), don't use exec() on Windows. If you want signals, fork(), and exec(), get rid of Windows and run a UNIX derivate (*BSD, Linux, ...) instead. If you can't get rid of Windows, use Windows API functions instead of the fragile emulations. See Win32, Win32::API, Win32::Process and others.

Alexander