The most important steps for any computer user is to always install updates, especially security updates, when they become available for your operating system. A common method that computer infections use to infect your computer are security vulnerabilities in your installed programs. The advice in this tutorial applies to all computer users and all operating systems, but we have tried to point out specific steps for various operating systems as it becomes necessary. Do not use the same password at every site, and use a password management program like Keepass to help you remember passwords.
Source: https://www.bleepingcomputer.com/tutorials/keep-your-computer-safe-online/