WakeupOnStandBy, Free Alarm Clock and Alarm Clock of Justice are good free clock programs for Windows computers, according to Gizmo's Freeware. These programs function even when the computer is hibernating or in standby mode.
WakeupOnStandBy wakes the computer from hibernation or standby mode at a time specified by the user. It then executes actions such as playing music or streaming media. A similar program, Alarm Clock of Justice, wakes the computer at the appointed time and plays a user-selected alarm tone. It also has a snooze option.
Free Alarm Clock offers multiple alarms, alarm looping and snoozing. Users may set different volumes and monitor settings for each alarm, and type reminders into a text box that appears when the alarm activates.