The first step is to install anti virus software on your computer, no matter what operating system is running, and make sure Anti virus definitions are updated automatically. Free anti virus software can be downloaded from reputable sources such as CNET.
Second, generate a separate administrator account for your computer, and use it only to install software from it. Do anything else with limited accounts can not affect the computer’s operating system.
Finally, use common sense. Do not open e-mail attachments that are not expecting. Do not buy software unusually cheap. Check the address or the address of the URL each time you visit a website. And keep in mind that banks will always call, never by e-mail, if there is a controversy along with your account.