HOW TO ERASE A PROTECTED PICTURE

Protected pictures cannot be erased using (erase),(sel. image) or (all erase) but they are all erased by formatting the memory card.

Unprotect them first. While viewing the picture, press [MENU] and select "Protect". Full details are in the "Protecting images" section of the manual (page 100 in my copy). If you need a manual, you can download one at
http://gdlp01.c-wss.com/gds/6/0300003266/01/PSSD1300IS_IXUS105IS_CUG_EN.pdf

theres a lock key in the memory card slide it upwards then re insert it and try again

You should do the same process like above to unprotect the images. Trying to delete is wrong.
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Before inserting your SD memory card, slide the write-switch to unlock position. Insert the SD card, go to ‘setup menu’, then ‘format’ , format the SD card. All pictures will be erased. Refer your manual on page 87.

Protected pictures cannot be erased using [ERASE],
[SEL. IMAGE] or [ALL ERASE], but they are all erased by
formatting.
• Go to Playback mode in the camera. Select the picture to be unlocked with the left or right arrow buttons, and to remove the protection select OFF with the up or down arrow button.

Protected pictures cannot be erased using [ERASE],
[SEL. IMAGE] or [ALL ERASE], but they are all erased by
formatting.
• Go to Playback mode in the camera. Select the picture to be unlocked with the left or right arrow buttons, and to remove the protection select ON with the up or down arrow button.

If the image has a small icon of a skeleton key along the bottom when viewing it, it means the image has been protected. You have to un-protect the image to erase it. This is done from the Playback Menu (the one with the arrow on the tab). Specific instructions are on page 115 in the manual. (Manual is available here if you don't have it.)

Formatting will erase all pictures, including protected images.

1. Turn on the camera
2. Press the menu button
3. Press the "right" pad control button
4. Then press the "down" to go to Setup (looks like a toolbox) then press "right" again
5. Then arrow down to the Internal Memory Tool and choose Format by pressing the Center Control Button in the middle of the Control Pad.
   
6. or, if you have a memory stick where the image is, select memory Stick Tool and choose Format by pressing the Center Control Button in the middle of the Control Pad.

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If all else fails, save your pics to your pc and then format your card