follow these few steps:
Open Start Menu >> Run, type regedit and press Enter, this will open the registry editor.
Navigate to the following path:
Note: If the registry key StorageDevicePolicies key does not exist, you will need to create it
Download this batch file called add.bat from here, and double click after download the key will be automatically added to registry.
Double click the key WriteProtect in the right pane and set the value to 0 in the Value Data Box and press OK button
Exit Registry, restart your computer and then again re-connect your USB pen drive on your computer. That is it, done.