Choosing a Linux based operating system for your PC is safer for a few basic reasons:
1. Fewer viruses are written for Linux. When a less then friendly developer creates a piece of malware, they are looking to do the most possible damage. This means they will design for the most popular operating system. This is, generally speaking, a version of Windows. Thousands of viruses have been designed for Windows, but the estimate for Linux based systems is about forty.
2. Windows users are more likely to run as admin. As a matter of fact for most Windows versions this is the default when you create the first account. To log in as the admin in a Linux flavor you have to be logged into the root account. What is the big deal about running as admin? The admin account has a lot more access to the system which means more access to the system and more ability to mess things up.
3. It is easier to run an executable file on Windows, and nearly impossible to tell them apart. There are only two different types of executable files, an .exe and a .scr. All you have to do is open an email to let an executable file run on Windows. To run the same file on a Linux system you will have to read the message, save the files, give it executable permission, and then run the file. That means that an end user is a lot less likely to open a file lightly. That also means less of the careless behaviors that lead to accidental downloads.