Try to avoid public devices. It is easier to ensure secure communications on your own devices, and you do not know who used a public device previously or what malware it may have installed on it. If you have to use a public computer, bring with you a bootable USB device. This device will work like a temporary operating system that allows you to work on the public computer without using its own functions. The content will be saved in the RAM, in the short memory of the computer, and is only valid for a single session. When you shut down the computer, there will be no data or activity saved on the public device.
Booting a device is also recommended when you want to use a different operating system. For example, you can install a Linux system on a booted USB device; after booting from the stick on your Windows computer, you will be actually working on a Linux system. But remember, there will be no data saved on your computer. Creating a bootable USB device is not easy, and if you decide to use this method, you should watch tutorials in the web.
You should also avoid free, open Wi-Fi connections, as you do not know who is logged in to the same connection and whether that person is trying to do you harm. When connecting into free Wi-Fi, use VPNs at all times to surf in the Internet. This provides a minimal of privacy.
One example of how to boot an USB device on a Windows 10 operating system is available here:
A Secure Alternative: Linux
‘Linux’ is an alternative operating system for computers and smartphones mostly used by computer scientists — one of the most secure ones available. Modern distributions — or software packages — can be installed and used as easily as other operating systems, and more common ones include ‘Ubuntu’, ‘openSUSE’, ‘Debian’, ‘Mint’ and ‘Elementary OS’.
Linux is free, open-source and flexible. Because everyone can help source code errors and security bugs, they will be unveiled and fixed faster than in other operating systems. And, because the system is not as commonly used as Windows or Apple, there are fewer viruses on the Linux platform. Every year, Linux publishes their list of the best Linux distributions.
A short explanation about Linux can be found at: https://www.youtube.com/watch?v=JsWQUOEL0N8.
Links for the distributions can be found here: tails.boum.org (ranked most secure, can also be used for an USB device), elementary.io (best design interface), www.ubuntu.com (popular and good for laptops), www.opensuse.org (user-friendly), www.debian.org (good for servers) and www.linuxmint.com (user-friendly).