Hourglass - Hourglass is the most advanced simple countdown timer for Windows.
T-Clock Redux - T-Clock Redux in an enhanced fork of Stoic Joker's T-Clock 2010 with ISO week number support...
SnapTimer - SnapTimer is a simple, free, portable countdown timer for Windows.
DS Clock - Keep your time synchronized with Atomic Time servers, using customizable digital desktop clock with westminster chimes.
Free Countdown Timer - Free Countdown Timer is a free, full-featured and user-friendly countdown timer for Windows
AlarmDJ - Online Alarm Clock - Use YouTube videos or MP3 files as alarm sound. Works offline.