Strong Encryption for Your USB Flashdrive - Windows
Yes, I know this page is titled "Truecrypt". Truecrypt is obsolete and out of develpment! Instead, you really should use Veracrypt!
Not only is Truecrypt obsolete and out of development, it had some minor flaws that could be exploited to reveal the contents of encrypted data. Veracrypt is based on Truecrypt, but with much more robust code and without those flaws.