I have nothing against any of the solutions presented here. They're all very helpful, thank you to the posters.
However, your main system is on Windows. Being on Windows, you have BitLocker built-in. In many ways this offers a more secure and effective solution than a third-party tool.
In current versions of Windows 11, Bitlocker is enabled by default.
This is important -- even for people that don't want to encrypt data
...Because it means that if your OS crashes and you do not have a backup key stored, your data will be gone. Even if you didn't choose to encrypt it, because it's now a default option.
If you do need to show the data is encrypted and you're running Windows, BitLocker is the best way to go, especially on Windows 11, because you gain the benefit of hardware-based (Trusted Platform Module TPM) encryption. BitLocker doesn't require TPM; however, once you've added that feature, it's even more secure.
Also, being that it's included free in Windows, you don't need to worry about cost or risk of pirated (as mentioned above).
Most importantly, it's tightly integrated in Windows, so that there is nothing special you must do and it's much easier to maintain and recover. Plus, being ubiquitous for 14+ years now, it's probably the most supported encryption for tools that help you recover in the event of catastrophe, etc.
After all, one of the most important considerations for secure/encrypted data, isn't just about managing it -- it's how likely you are to get it back if something goes wrong. For this reason, ubiquitous tech is the best route.
I hope that helps 🙂