‘W’ application prevents server reboot.

On several remote servers, I have scheduled automatic shutdown and reboot tasks every Sunday evening. Occasionally, the reboot fails and hangs on an application simply titled “W”. I’ve searched high and low, but can’t figure out what this darn “W”application is and why it is causing my reboot to stall. After I End Task several times, the reboot continues but the Event Viewer has nothing to show. I can email screen prints of this actual problem to anyone who can help. I’m running NT 4.0, SP4.