Below is how to protect data on USB flash drive free you can use.
Bitlocker. This tool can protect the data on your USB drive by encrypting it.
Plug your USB Flash Drive into a USB port.
Click start and click Computer.
Right-Click on your Flash Drive, and click Turn on BitLocker.
A new screen will pop up, under “Choose how you want to unlock this drive” click on either Use a password to unlock the drive, or, Use my smart card to unlock the drive.
Click Next and under “How do you want to store your recovery key?” choose either Save the recovery key to a file or Print the recovery key.
Choose the location you want the key saved, click Save.
Click Next, and next screen will ask “are you ready to encrypt this drive?”.
Click Start Encrypting.
How to protect data on USB flash drive free with bitlocker
If you don’t want BitLocker to protect your Flash Drive, you can use the following steps:
Open control panel.
Click on System and Security, and click BitLocker Drive Encryption.
Find your Flash Drive.
Click Turn Off BitLocker.
A screen will pop up and click yes.