I have 600 photos on my camera and I want to delete all photos. At the moment the photos are protected files, I can unprotect each photo and then delete but thiswould take me ages. Why can I not unprotect all photos and then delete all .

Unprotect the photos first. See pages 194-195 of the manual: http://gdlp01.c-wss.com/gds/0/0300004730/02/eosrt3-eos1100d-im2-c-en.pdf

Unprotect the files by pressing the key button while in playback mode. See page 119 of the manual at http://www.nikonusa.com/pdf/manuals/dslr/D100_en.pdf

The protect function allows a user to protect a picture from accidental deletion. To unprotect a picture on your camera, scroll to the protected picture that you want to delete, then press the Menu button (the button to the right of the Play button.) Scroll down the menu and you should come to an option that allows you to Protect/Unprotect the picture. Since your picture is currently protected, deselect that option. You should then be able to delete the picture normally.

Alternatively, you could also format the memory card, however this deletes ALL photos and data you have on the memory card. If you are trying to completely clear the memory, this is the best way. After turning on your camera, simply press the Menu button, scroll to Setup, then scroll down to Format. Select Format, it will ask you if you want to format the memory card, or the camera's built-in memory. Format whichever one you want to clear, if you are using a memory card then your pictures are stored on the memory card. It will take a few seconds to format.

Hope this helps.

While viewing the photo to be deleted, press the trashcan button. If the photo is protected, unprotect it first by pressing MENU and selecting PROTECT.
If you want to delete all photo, format the card.
If you need a manual, you may download a copy here.

You have to select each protected photo and and unprotect it.
Of course the 'protect' function is there to protect photos from (accidental) deletion.

Please unprotect the images and try to delete the files. I have attached the Manual of the Camera where you can get the instructions to unprotect the images.

http://www.docs.sony.com/release/DSCS750_handbook.pdf

Please refer to page # 43 of the above Manual to unprotect the images.

To delete all or just one of the pics on the memory card -- go to the play mode and use the Q Menu on the very bottom right -- you can select your choice from there.

In play you can also go to Menu and Protection and select if you want all or one photo protected.

Hope that helps!
Took me a while to figure it out!

Easy solution:

1) Put the sd card into your computer
2) Copy all the photos to your computer. User Windows Explorer to just drag the folders from the card.
3) Format the card

If you insist on having the photos back on the card, then just copy them back to the card using Windows Explorer reversing step 2.

Sounds like you protected the picture. Either unprotect it first, or else just format the card.

remove the protection then delete