Well, Windows itself, lets you disable sleep, wake and power. You can often disable them from BIOS (less so the power), which is generally part of ACPI. You can get
a physical key lock or use autohotkey to disable the windows key.
Microsoft Windows XP users
By default, Microsoft Windows XP will prompt you what to do when the power button is pressed on the keyboard. If you wish to change this setting, follow the below steps.
Click Start / Settings / Open the Control panel
Within the Control Panel click Power Options
In the Power Options Properties window, click the Advanced tab.
Under Power buttons, click the down arrow under "When I press the power button on my computer" and/or "When I press the sleep button on my computer" and select the action you wish to perform when pressing the key.