Check the physical write-protect switch on the pen drive and turn it off
Try a different USB port or another computer
Open Command Prompt as administrator
Type `diskpart`
Type `list disk`
Type `select disk X` replacing X with the pen drive number
Type `attributes disk clear readonly`
Type `exit`
Open Registry Editor
Go to `HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlStorageDevicePolicies`
Set `WriteProtect` to `0`
If `StorageDevicePolicies` does not exist, create it and add a `DWORD (32-bit)` value named `WriteProtect` with data `0`
Run `chkdsk X: /f` replacing X with the pen drive drive letter
Format the pen drive if needed
Check for malware or security software blocking writes
Replace the pen drive if it remains write-protected