The camera sometimes freezes when I insert the card and when it doesn't it says the memory card is not recognized.

I press the on/off switch and nothing happens.

Make sure the batteries are inserted correctly. If they are, make sure that they are not dead. If they are dead replace them. If the device still does not extend make sure that there are not any obstructions that would prevent the lens from extending. If the lens will still not extend you may need to replace the lens assembly.