I tried putting tape over the tab on the ad card and it still shows write protect on the 3DS. I did put sd card in my computer and was able to copy a song on it so now I am thinking its a problem with

Normally there's a small tab that needs to be slid to the opposite side.

hmmm you should try the followings:

First insert your SD card and try to make a copy of your pics from camera memory to your SD card. And then use this SD card to your computer.

Or Using Camera manufacturer and model no. search some driver and software for you so that you can transfer the pics to computer.

if still not fix, let me know your manufacturer and model no.

Thanks
iqbal

SD cards have a slide switch along one edge. The position farthest from the metal contacts locks the card, protecting it from writes. The position nearest the contacts unlocks the card.

Go into setting and and enable it

There are two possibilities that I can think of. 1) The SD card is full. You will need to copy the pictures off the SD card and onto your computer, then format the card. You can probably do this in the camera, but MAKE SURE you have copied the pictures you want to your computer because the format will erase everything. 2) The SD card is write protected. Look closely at the SD card there is a little slide switch that "locks" the SD card so that your camera cannot put any pictures on it. This slide switch must be in the unlocked position (or NOT locked).
Hope this helps.

It won't do anything. Downloading an app for the Wii, putting it on your SD card, and then putting it into your 3DS will not do a thing.

Removing the write protection depends on the source of the problem.
Broadly speaking, it can be any of the following scenarios

1. There is a write-protection tab on the mini sd card HOLDER. Every time you insert this into your PC or card holder, this tab slides to the write protect position. Either keep resetting, inserting & reinserting until it doesn't slide or tape it down.
2. There is nothing wrong with the mini sd card. Simply locate the write protection key and push it.
3. The mini sd card has some error: Go for a low level formatting.
4. The card has virus: Remove the virus. The link for the steps is present in the related link at the bottom of the article.
   

There is an easy way to solve this problem: Simply put the yellow lock in the middle of its slider. No sticky tape required, as shown below. But if your still having the same problem i suggest you try the sticky tape.

problem is only that small moveable yellow lock switch is not making, just put sellotape over it maybe two layers needed to make switch.
== Answer == Even though what is written below may work, the problem is probably that on the card reader (if you have one) there is a small switch that has lock written on the side. If this is pushed down, the drive is write protected, push it in the opposite direction and it may fix your problem I had the same problem with several cards but eventually found a way around it. DON'T buy a new one!

Make sure the SD card lock is 'off' and then use thin, opaque sticky tape (ie non see-through; eg insulation tape) to cover the whole gap but keep clear of the metal contacts at the back.

Your card should work fine now... don't know why this has to be done, but it works! Additional info:
Reason #1,
the mechanical lock switch accidentally moves to the "locked" position during insertion due to the poor quality of the switch. Hence, by taping it, you are actually preventing the lock switch to travel towards the lock position. i.e. downwards.

Reason #2
If the above fails, it is likely your SD card reader/writer's fault. But don't discard it or buy a new one yet. Allow me to explain the mechanical design of the SD card lock mechanism. So that you may choose to repair it if you want to. You will need a small paper clip and screw-driver to open your card reader. (Don't proceed if your card reader is still under warranty, please return/exchange with manufacturer) There is a mechanical switch very much like a micro push button (I wish I could show you the picture/drawing). Anyway, depending on the position of the lock switch. You either push or release this micro push button inside the SD card reader.
Due to mechanical wear and tear, or some forceful insertion of the SD card, the micro push button is in its "open" circuit position, i.e. write-protected. In order to make the SD card reader writable, we will need to "close" the circuit. (Note: this is an irreversible process as I will be telling you how to remove the write-protection feature of your SD card reader. Once you do this, you would be unable to use the SD card lock switch to lock your data. So, just be careful not to accidentally delete your data)
To proceed, you need to remove the main circuit board from the SD card reader/writer enclosure. The location of the micro push button switch is the same location as the unlock position of the SD card when inserted in the SD card reader/writer. From the BACK of the exposed SD card reader, insert the unfolded paper clip (same way when you try to poke something like a device reset button) except, that it has to be long enough to allow the micro switch to touch together for contact. Then insert the SD card. Once the contact is "closed", your SD card reader/writer can write again. I understand that without a drawing, this may not be very helpful. Please provide suggestions or better explanation if you can. Thanks.

Or, just tape the lock switch to unlocked. This also works for SD cards in normal size. back up all the files u have on ur card then follow these steps

1. Go to Control Panel
2. Go to Administrative tools
3. Go to Computer management
4. From the tree menu on the left select Disk Management
5. Now on the right side you will have a list of all storage devices connected to your computer. Select the one that is your mini SD card. BE CAREFUL WHEN CHOOSING THIS BECAUSE YOU COULD FORMAT YOUR HARDDRIVE. Double check the name in My Computer
6. Right click on the SD card and select format. A new window will pop up showing format options. Select FAT32 from the file system drop down and check the quick format option and then click on OK
7. Enjoy your mini SD card without that annoying write protection

Removing the write protection depends on the source of the problem.
Broadly speaking, it can be any of the following scenarios

1. There is a write-protection tab on the mini sd card HOLDER. Every time you insert this into your PC or card holder, this tab slides to the write protect position. Either keep resetting, inserting & reinserting until it doesn't slide or tape it down.
2. There is nothing wrong with the mini sd card. Simply locate the write protection key and push it.
3. The mini sd card has some error: Go for a low level formatting.
4. The card has virus: Remove the virus. The link for the steps is present in the related link at the bottom of the article.
   

There is an easy way to solve this problem: Simply put the yellow lock in the middle of its slider. No sticky tape required, as shown below. But if your still having the same problem i suggest you try the sticky tape.

problem is only that small moveable yellow lock switch is not making, just put sellotape over it maybe two layers needed to make switch.
== Answer == Even though what is written below may work, the problem is probably that on the card reader (if you have one) there is a small switch that has lock written on the side. If this is pushed down, the drive is write protected, push it in the opposite direction and it may fix your problem I had the same problem with several cards but eventually found a way around it. DON'T buy a new one!

Make sure the SD card lock is 'off' and then use thin, opaque sticky tape (ie non see-through; eg insulation tape) to cover the whole gap but keep clear of the metal contacts at the back.

Your card should work fine now... don't know why this has to be done, but it works! Additional info:
Reason #1,
the mechanical lock switch accidentally moves to the "locked" position during insertion due to the poor quality of the switch. Hence, by taping it, you are actually preventing the lock switch to travel towards the lock position. i.e. downwards.

I think you can either format the sd card using the phone, or simply put four folders on your sd card with your computer. The folders are named

my_music
my_picture
my_sound
my_video

you just put the mp3s in the my_music folder. You will have problems with some files if they are right protected.

thought the cards have a little tab on them so they can be "write protected" it is a little plastic tab on the side of the memory card you slide up and down. I know most SD cards have it, CF cards dont so if its anything besides SD memory its probobly the memory card or some little switch or somthing in the camera that tells the camera when the card is in the "Locked" or "Write protected" mode.

Looking at my SD memory cards they have a little arrow on the edge and they say "Lock" pointing down, the slider is up. Move yours both ways, maybe it has a bad connection in the card (im not sure what it actualy does) or its in a position the camera thinks its locked?