Power the unit off (press and hold the power button until the blue light goes off). Then, press and hold the power button for 3 full seconds and then release. You should see a recovery menu be displayed. If you hold the power button for too long (and the blue light goes back off), you can simply try again. From this menu, select to enter BIOS Setup. From there, choose to reset the BIOS configuration. Save and exit. This should get you going again.
If you cannot get the menu to appear, you may be well and truly dead. How long have you owned this ICS?