Some USB sticks have a switch that allows you to lock the drive. If you can find the switch, you can unlock it and remove the write protection from your drive.
You should check the Permissions setting: Open the Windows Explorer > right-click on the drive > click Properties > go to the Security Tab > and click on Edit > Select your username and check if you have Write Permissions. If you don’t, check the box for “Full” for full permissions.
Format the drive from a DOS Prompt. Check to be sure you know what drive letter is being assigned to the stick. Then go to Start > type: cmd > right click on cmd.exe > Run as Administrator > type "format space drive-letter colon" ( format x: ) and press ENTER. (Where X is the drive letter assigned to the stick).
See if any of those things work.
