Hourglass - Hourglass is the most advanced simple countdown timer for Windows.
TimeLeft - TimeLeft is a versatile desktop utility - it can be used as a countdown clock, reminder, clock...
Free Countdown Timer - Free Countdown Timer is a free, full-featured and user-friendly countdown timer for Windows
NetTime - nettime is a time & attendance software solution.
LClock - Longhorn systray clock program
Free Alarm Clock - Free Alarm Clock is a free, full-featured and user-friendly computer alarm clock for Windows.