The write protection feature exists to protect sensitive data that may be stored on memory devices, such as an SD card. Turning on the feature will prevent anyone from modifying the files on your card, whether they are important text documents or just family photos. If the feature has been accidentally turned on, or you are using someone else's card, there are a few different options for removing the write protection option.
Feel along the left and right edges of the SD card to determine if it has a physical protection switch. Push the plastic switch toward the unlock icon to remove the write protection option.
Insert the SD card into your computer's card reader. Click "Open a folder to view" files. Double-click any of the card's files and wait to see if the write protection error appears.
Right-click the file and click "Properties." Click the "General" tab. Remove the check mark from the box named "Read Only" if it is currently checked. Click "Apply."
Click the file again to see if it remains write protected. Access the Start menu and type "regedit" in the search field. Click the registry icon. In Windows XP you will instead need to click "Run" and then enter "regedit" in the text field.
Access the folder named "HKEY_LOCAL_MACHINE" and then open the folders labelled "SYSTEM," "CurrentControlSet" and "Control." Look through the list of sub folders and see if the "StorageDevicePolicies" folder is listed.
Right-click an empty area of the window if the folder is not present. Choose "New" and "Key." Enter "StorageDevicePolicies" in the "Name" text field and press "Enter."
Open the folder and then right-click the white area at the right side of the screen. Click "New" and then "DWORD." Enter "WriteProtect" in the "Name" field. Type "1" in the "Value Data" field and click "OK."
Close the registry editor and return to the SD card's window. Click a file and see if the write protection error appears. Close the window and open the Start menu. Click "Computer."
Right-click the SD card's drive letter and select "Format." Click "OK" to completely format the card and return it to its factory settings.
Not all computers include an internal card reader. External card readers that connect to your computer's USB port are available through electronics stores.
While formatting the SD card removes the write protection option, it will also completely erase all the data contained on the card.