My 7 year old daughter has used her camera, and some photos and viseos have a green key on the screen. Is it possible to remove the "lock" so the photos and videos can be deleted? I have loaded all the contents of the memory card onto my laptop-and selected delete but these items with the green key are still there. thank you.

What make and model camera? On most cameras you unprotect a picture the same way you protected it, possibly by pushing a "protect" button. No matter what, you can clear everything off the card by formatting it. Cards should be formatted each time after you download pictures to a computer instead of deleting individual pictures. FixYa is full of people asking how to salvage pictures from cards they didn't format.

Akima is right. You can unprotect a picture by just pressing a button on the camera . Also, the best option when you have used the card is to format the card when you have to reuse it.

Refer this article if you have some problem in your card.

http://hubpages.com/hub/Few-Tips-To-Protect-Your-Memory-Card-From-Corruption