Hi there,
plug the memory card to a card reader
Get into the Registry - Press Start -> Run, enter regedit, press Ok
Click on My Computer.
Then press File -> Export, give some file name to backup the registry. Just incase you ever need to rollback.
Navigate to HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Control/StorageDevicePolicies
In the right pane select "writeprotect"
RESET the value to '0'
Thanks