Protect and secure your Windows computer: A practical guide

Computer security is about protecting a computer from unauthorized use, malware, and espionage. For most people data security is at least as important, i.e. not losing irreplaceable files such as private photos and videos. Data security depends on computer security, but not vice versa. Even if you don’t have a single irreplaceable file on your computer but use a web browser to check your emails or log in to your bank, for example, you still benefit from computer security.

No amount of antivirus software, encryption, and other computer protection can protect your priceless files from being lost in a fire or stolen, for example. It’s little comfort that a thief can’t look at your holiday photos when you can’t because you had no backup.

Viruses, Trojans, and other malware were more common 15 years ago, but cause more damage today. The most common category of malware to fall victim to today is ransomware, which encrypts all the contents of your computer and demands a ransom so you don’t throw away the key.

Ransomware costs society billions every year. For home users, the sums required are astronomical, and even those who pay risk being caught out as some extortion programs are simply deceptive and never save an encryption key.

If you run Windows, a good antivirus program is still recommended, although the built-in Windows Defender function is now really competent at stopping known malware.

As well as often being slightly better at detecting known malware, the best antivirus programs have features that can stop previously unknown malware from constantly monitoring what’s happening on your computer. For example, they can detect that files are being encrypted and quickly stop the program performing the encryption. If it’s ransomware, it may only have time to encrypt a few files, and if it’s something legitimate (you may have chosen to encrypt sensitive files), just unblock it.