Easy Timer is a straightforward and highly configurable alarm clock.
At its simplest you can launch the program, enter an alarm time and click "Activate". Easy Timer displays a clock that will let you keep an eye on the time, if you like, and when it hits your defined time the program will play an alarm sound, 3 times.
If you're not happy with that, though, just about every aspect of the program's operation can be tweaked.
You can customise the look of the clock window, for instance. And you're able to set this to be always on top of other windows, or to minimise to the system tray.
If you don't like the default alarm sound, then there are 34 others to choose from, or you can point the program to the audio file of your choice (as long as it's in WAV format). You can also set the alarm playback, even the stereo balance.
And you can have the alarm sound play a specific number of times, optionally repeating after a few minutes, or just tell the program to play the alarm until it's deactivated. There's even an option to display a simple message along with the alarm, perhaps handy as a quick reminder of whatever it is that you need to do.