To remove write protection:
Open Start Menu >> Run, type regedit and press Enter. This will open the registry editor.
Navigate to the following path:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\StorageDevicePolicies
Double click the key WriteProtect in the right pane and set the value to 0
In the Data Value Box, press OK
Exit Registry, restart your computer and then re-connect your USB pen drive to your computer.