Launching multiple PHP threads via Scheduled Tasks

I've got a script that downloads files queued from a server, and it's launched by a Windows Scheduled Task that launches every minute. My understanding of the default behavior is that if the task is still running a minute later when it's time to launch again, a duplicate thread will not be launched. The remote server administrator wants me to launch multiple threads all day - in my mind the wrong choice, since multiple download threads slow everyone one, but that's what he wants. Anyone know if there's a way to make Windows Scheduled Task launch a new thread of the PHP script, regardless of whether it's already running?