Press your Windows key and R at the same time and when the Run box opens, type regedit then press the Enter key.
When the Registry opens, select Export from the File menu and note the name and location of the backup you are about tocreate in case anything goes wrong.
Themn, navigating as you would in Windows Explorer, go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\StorageDevicePolicies and find the Write Protect key in the right hand pane. Set the value to 0 (zero) then go to the Data Value box and click OK.
Leave the Registry from File>Exit then restart the computer. Hope that makes a difference.