Are you running your Perl script from within the same cmd.exe that you are running the commands in? Or are you doing something different such as double-clicking on an icon (or even just running it in a different cmd.exe)? If you are doing something different, then are you running the cmd.exe that it works in as adminsitrator or with some other form of elevated permissions? Have you checked the Event Logs? You might also want to turn security auditing on to see if anything shows up in the security Event Logs.