This most likely that your files in cards become Read Only. Many people are having same problem. Solution are:

Solution 1:

Start > Run > cmd
type "diskpart" -> runs diskpart.exe from system folder
type "list volume" -> now you see all your connected drives, see which one is the drive
type "select volume #" -> # being the letter of your drive
type "attributes disk clear readonly" -> removing the protection
Then open your SD, you can now edit, delete, move files.

Solution 2:

Plunge this drive or memory card to a computer. (Of course, you should use a card Reader to connect your memory card.)
Click “Start” on the taskbar to open “Run” and type in “regedit”.
Hit “HKEY_LOCAL_MACHINE” to expand “System”.
Find “Current Control Set” in “System” list to click “Control”.
Check whether there is a key named “Storage Device Policies” to change the digit in the “DWORD value” box into "0" and press “OK”. But, if you cannot find the key named “Storage Device Policies”, you are supposed to create a one: right click “Control” to create a new key and name it as “Storage Device Policies”=> right click this new key to open “DWORD Value” and name it as “write protect”=> Double click it to change number.

Suppose to be DWORD. What you have there is QWORD, for 64 bit. It will not harm anything. You can always delete the registry if not working. Just make sure it is the one you created.

Since you have the files save somewhere else, have you tried to format the card using command prompt (not using Windows GUI)?

Sometimes the problem is on the SD card Lock/Unlock slider itself. Though it is fully slide to unlock, sometimes the PC look at is as Read Only. Try to slide it just a bit to Lock position but not all the way to Lock. Sometimes this works.