After locking memory card, do I then unlock it to take pictures and will that then erase the memory card or can you tell me how to so

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

The most common cause for telling you that the card is locked is having the tiny slide switch on the side of the card in the wrong position.
- see photo below:
Set the lock slider to locked or unlocked.

• The down position will enable write-protection, locking the card.
• The up position will unlock the card, enabling you to save and erase data on the card

the tiny slider is labeled with "Lock"
SD memory card lock Nikon Knowledgebase

The camera is actually saying that the internal memory of the camera (which is very small) is full, not your card. Here's what to do....with no card in the camera, go into the menu and find "format"(may be called "initialize") and follow the on-screen instructions to erase the internal memory. Once that's done, your card should work properly.

Your question does not display properly, but I'll assume that the error message is telling you that your memory card is locked and cannot be written to.

Make sure that the camera is turned off and then remove the SD memory card from the camera.

Look at the card carefully, and you'll see a small switch used to lock the card to protect the data from being deleted/overwritten. Slide it fully to the unlocked position; if it's already there then slide it fully to locked and then fully to unlocked.

If this doesn't work then remove the card again and use a CLEAN pencil eraser on the electrical contacts to clean them. Do not use a dirty eraser as the graphite on the eraser is electrically conductive and can ruin your SD card. Also do not use an ink eraser as they're very abrasive and usually have conductive metal particles in them.

If this still does not work then you need to buy or borrow another SD card and make sure that it's switch is fully unlocked. If it works then you have a faulty SD card and must replace it with a new one, if not then you have a camera fault and this is beyond the scope of any DIY/FixYa repair.

I hope that my posting has assisted you and in return I ask only that you please take a moment to rate my answer.

Move the slide switch on the side of the memory card.

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.

Two possible solutions.

1. Apple users have reported that the switch on the memory cards performs the file lock function in either extreme positions Lock/Unlock. In some cases they have achieved success in centering the Lock/Unlock switch allowing access to the read/write operation of the memory card

2. Connect to PC
Access drive via windows explorer
Right click on drive (MEMORY CARD)
Select properties
Confirm that RO (Read Only) is not selected.
Selected RO
Try reading card
Repeat properties un-select RO
Try deleting files

If not successful card is likely defective

Hope this helps?

Make sure your camera is off.....Open flap to memory card.....On the side of your card you will see a little TAB that you can slide up and down....Your card is in the LOCKED POSITION which means you can't accidentally erase pictures stored on the card.....Simply slde the tab to the opposite position where it is now and you will have an unlocked card.....

Your memory card has a small white "switch" on the side. Move the switch and your card will unlock. It is a saftey so you don't erase anything accidentaly.

There is a tiny switch located on the side of the memory card, might even say lock on it or beside it. Just flick the switch opposite of the way it is now and it should work fine after that. There might even be a small arrow showing which way to switch it. The reason for the lock button is "just" for this, so you don't accidentally erase some wanted pictures or someone else.