This happens when some virus or script which applies the registry hack to make any drive write protect when connected to the computer, In that case follow the procedure below to remove write protection from your pen drive.
1. Open Start Menu >> Run, type regedit and press Enter, this will open the registry editor.
2. Navigate to the following path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\StorageDevicePolicies
Note: If the registry key Storage Device Policies key does not exist, you will need to create it
Download this batch file called add.bat from here Download, 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
4. Exit Registry, restart your computer and then again re-connect your USB pen drive on your computer. That is it, done.
If you don’t find StorageDevicePolicies key in the registry, the best way is to create it yourself. Below is the procedure.
Start the Registry Editor Go to the HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Control key
If there is no key called StorageDevicePolicies, create it.
You do this by right-clicking the HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Control key, and selecting New > Key from the menu.
Select the StorageDevicePolicies key
From the menu select Edit > New > DWORD Value
Name the new value WriteProtect
Right-click the WriteProtect value and choose Modify
In the Value Data: box enter 1
Exit the registry editor, and restart your computer
To reverse, just delete the new WriteProtect value (or set the value to 0) and restart the computer.