Hello and welcome to Tom's Hardware Forums.
Press your Windows key and R together then in the Open box, type regedit and press Enter. Choose Export from the File menu thennote the name and location of the crucial back you're about to make - you may need it if something goes wrong but if you follow these steps, nothing will.
Navigate to the following:
Double click on the WriteProtect string and change the Value Data’box from 1 to 0.
If there are any spaces between the words '"StorageDevicePolicies'", remove them because they shouldn't be there.
Save, exit and restart the system and try your stick again. Have you already checked it for a tiny switch?