If you are trying to take off the Laptop Keyboard of your Compaq Presario 900 laptop, my suggestions is NO.
DO NOT pry any keys off a laptop keyboard such as Acer Laptop Keyboard and Gateway Laptop Keyboard. The keys are nearly impossible to replace! The general procedure is to remove the plastic trim panel at the top of the laptop, under the display and covering the hinges (the one with the ON/OFF switch, indicator lights, etc.). There are tiny slits in the panel so you can insert a plastic tool to pry up the panel. Once the panel is removed, you will typically see 2 screws that need to be removed (sometimes there are none). The top of the Compaq Laptop Keyboard assembly can then be gently flipped up towards you and lifted up slightly. You will then need to remove the cable. The cable is secured in place - there are usually TINY tabs which need to be lifted up, or a hinged clamp which secure the cable in place. This is careful, delicate work. If possible, practice on a junker/dead laptop first....Check the HP/Compaq website for a service manual for your model. If one is available, download it and read. There will be clear photos and instructions for removal and replacement.