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.

Before I go further, kindly confirm this is correct?

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.

Tried both,... still the same. Changed to DWORD, same.

Well, went to friend's office to test.

Tested on another usb card reader, the same issues. Luckily, there was a onboard card reader from those branded pc and that card reader actually can format all 3 cards.

However, after formatting, the 8GB card still cannot be detected on the camera. With my own card reader and pc, i still face the same issue with all 3 cards. The funny thing is, I have other cards which have not been used with the camera, those i can format, delete, copy paste etc with the same card reader and pc.

Mixed result. Very confusing. Wondering if I need to getting a new onboard card reader instead of those usb type? I bought this for rm80+ from viewnet, ain't those tiny cheap usb card reader. But it also does not last. Had it for 2 years.