Digital Camera Repair Questions? Ask a Camera Expert.
How are you trying to view the pictures (via the computer or via the camera?)
The process is explained on your user manual (page 111-112), a copy can be found here.
Go to the image which is protected, press the func/set round button located in the centre of the control dial to the right of the display, then select the key icon down the left hand side, press the func/set button again and you should then be able to delete the image.
The manual also shows you how to do this by selecting more than one image in one go.
Let me know if you need anything further.
Just wanted to follow up to see how you got on, and if you need anything further?