First of all, keep your computer healthy. Help it avoid viruses. You’ll see them given many different names, such as ‘malware’ and ‘spyware’.
But viruses are basically all programs or files with one thing in common – they’re out to cause trouble by gaining access to your device and attacking personal data. Your computer’s built-in ‘firewall’ will keep some of them out, so make sure it’s turned on.
And you should install anti-virus software which – if you keep it up to date – will usually block most other threats. You can buy anti-virus software from a computer shop or download it online (sometimes for free). Once installed, the software will protect against new viruses with regular updates. These updates may occur automatically or you’ll be prompted to install them.