Every computer connected to the internet is vulnerable to viruses, forcing us to pay the software protection industry's charges to stay safe.
But it's possible to get legal, professional-quality antivirus and other protective software for free. Here's our rundown of the best free antivirus and free internet security software.
In this guide
Always be careful to check any software you put on your computer is suitable and compatible with your existing set-up. No liability can be accepted for any individual problems caused by acting upon the information given.
Internet security software to protect your computer is a must these days. But you can boost your level of protection, without any new programs:
1 Keep your software up to date
Even if your computer comes off the shelf with a level of protection, threats change daily. So it's imperative you keep it up-to-date or else it's useless.
For Windows 7, just click on "Start", go to Control Panel and click the "Windows Update" icon, where it will show you if there are any updates for your PC. The same goes for users with Windows 8, 8.1 or XP.
Even dedicated antivirus software (see the top free protection below) needs to be updated, and do a full system scan once a week.
Mac users (and Linux users) have slightly less to worry about in terms of viruses, as there still aren't as many floating about for them. Nonetheless, Mac users should grab free antivirus software too.
2 Protect your identity online
With more and more of us using the web to bank online and do other sensitive tasks, coming up with solid passwords is more vital than ever.
Firstly, don't use the same login for lots of sites. If one falls into the wrong hands, your whole online life is up for grabs. Try picking one and add a few letters related specifically to each site you're logging into.
Ensure you change your passwords frequently. Use a free password generator to get a completely random, but secure password.
3 Switch it off!
Switching your computer off when you aren't using it doesn't just save energy, it stops others accessing it. At the very least, disconnect your broadband when you're not online.
While your PC's on, and after you've been browsing, is a prime time for malware (malicious software) attacks. So switching it off is a good preventative measure.
4Don't open unknown email attachments
Most web crime still happens via email, so be on guard when checking yours. Don't open any attachments you're not expecting, or click any random links you find in the text (see the Phishing Scams guide).
If you're unsure if a site's legit, whack the name into Google and see what comes up. It may be listed as a bad 'un.
How can I filter out spam?
Most big email clients such as Google, Outlook and Yahoo! have their own filtering system to stop spam. Check your settings and make sure the filter is switched on.
Blocking spam's not an exact science, and important emails may also be blocked.
The way around this is to make sure you've added senders whose emails you'd like to receive to your "accepted list". The same goes for this site's weekly MoneySaving email; its combination of freebies, money, mortgage and debt info means it can easily get caught in spam filters.
For those that don't get it, you can add yourself to the distribution list at moneysavingexpert.com/tips.
How can I protect my email address?
Only give out your email address to people you know. Don't post it on public internet forums (including MoneySavingExpert.com's) or chat rooms. Spammers often use software robots, or "bots", to read all forums, store any emails and spam them.
Can email rules block spam?
If you download your emails to a computer, eg, using Microsoft's Outlook, you can create rules to stop common spam by entering key words, eg, VIAGRA, so those emails are automatically filtered. But spammers try to beat it through mis-spelling words or using numbers in place of letters, eg, V14GRA, so you'll have to block out other combinations too.
5 Only download software from trusted websites
Looking for a piece of software? Find out which company makes it first and then go to its site to get it, rather than a third party site found via Google. For smaller free or shareware programs, try using big sites such as Download.com, rather than just getting them from anywhere that shows up.
For advanced downloaders (OK, nerds): when using
If you're not protected and someone uses your computer to get passwords, or accesses your bank account or other financial products, you may find it harder to get a refund.
The burden of proof's on the bank to show you didn't act with care, but it's best to be safe. For more on what to do if you think you've been defrauded, read the ID Fraud Protection guide.
Know all the main threats?
Threats to your computer come in different guises with various funky names. Collectively, they're considered malicious software, or "malware". The main types are:
Viruses. Hidden programs that wreak havoc
These are transmitted via websites, email attachments, directly over the internet or via any other removable media. They hide in applications or files and spread from computer to computer, generally wreaking havoc wherever they get the chance.
Trojans. Bugs within harmless-looking files
Trojan (horses) are hidden within a harmless-looking file (eg, a picture of a celebrity) or progam (ironically, they're often dressed up as antivirus tools). They aim to trick the user into installing malicious software, like spyware or adware.
Worms. Can drill in via open web connections
Worms take advantage of any open internet connection. They try to sneak in and replicate on the computer. Once loaded, they often start to send spam email from your computer without your knowledge.
Who's behind malware?
It's a common misconception that producing computer viruses is the domain of angst-ridden web kids with little to do, showing off to their equally reclusive peers. While there may have been some truth in this at the beginning, and of course it still happens, these days it's often about big criminal business.
What happens with stolen information?
Cracking into your computer can reveal a breadth of information about you. It could include your bank details for ID fraud or for just directly taking your cash.
A program could grab all the emails in your address book/contacts list to find real addresses to sell to spammers. These people may well then be emailed from your address
What happens when a virus controls my computer?
Some viruses allow your computer to be controlled via a 'DDOS' attack. This is where a website is closed down due to simulated, simultaneous use by billions of users. This can be for political reasons, a ransom, to hurt competitors or "just for fun".
Many people whose computers cause this are unaware it's happening. MoneySavingExpert.com has been hit by such an attack. Ironically, some of the people denied access for three days could've been contributing to the closure via hidden viruses on their systems.
Pay for antivirus software from biggies like Symantec/Norton or Kaspersky and it'll cost around £40 per year. Yet you can get free software which, while not quite as effective as paid-for programs, still keeps on top of threats. Regardless of which route you take, remember:
Hackers develop new bugs constantly. All these free antivirus services offer regular updates, so make sure you get them.
It's not just about how up-to-date your software is. If you're not using it, what's the point? Try to fit in a full "on-demand" scan once a week, where the virus scanner flicks through all the files on your hard drive. This should make sure nothing slips through the net.
Antivirus: Free PC software downloads
McAfee. Normally paid-for, but free to MBNA & HSBC customers
All MBNA cardholders signed up for Online Card Services can get a year's free access to McAfee's Online Banking Suit, which includes its antivirus, spyware and adware programs, and more.
It's £60, thought you can get it cheaper via offers. If you don't cancel before the free year's up, it takes £30 for the next year's access (50% off the RRP).
And HSBC customers can get 12 months' McAfee Virus Scan Plus, (RRP £40), for nowt. Forumites are sceptical about it, though.
Kaspersky. Normally paid-for - free to Barclays customers
Barclays' online banking customers can grab a free 12-month Kaspersky Internet Security antivirus subscription (RRP £50).
It comes very highly-rated by various tech publications, so it's a must-have if you bank with Barclays. You can renew it free after the first year, but you'll need to reactivate it again.
Microsoft's Security Essentials antivirus package is completely free to users of "genuine Windows machines", so it'll verify your copy. Four versions are available, for XP, Vista, Windows 7 and Windows 8.1.
The software's unobtrusive and provides quick and comprehensive protection from viruses, trojans, and spyware. For casual Windows users, it feels and runs like part of the regular operating system rather than an added extra. But some experts say it's not as good as it used to be.
For Windows 8, Windows Defender replaces Microsoft Security Essentials. Windows Defender runs in the background and tells you when you need to take specific action. You can use it anytime to search for malware if your computer isn’t working properly, but reviews are mixed on how thorough the scans actually are.
Avast 2014- totally free
Alwil's Avast 2014 antivirus is the latest version and boasts an improved interface and better detection. So much so, it's leapfrogged Avira's Antivirus in our rankings.
Avira Antivirus - totally free
The free antivirus software of choice for many techies, Avira's won many tech publications' free antivirus round-ups by providing both the most thorough and fastest software protection. If you have the know-how, it'll do everything you want it to, but it's best for those that know their way around a PC.
AVG Free - totally free
The protection provided by the current version of AVG AntiVirus Free 2014 is reasonably thorough, though it doesn't offer any real tech support.
AVG is unobtrusive, doesn't use too many resources, and will regularly auto-update. It includes LinkScanner - real-time threat detection, which checks links out when you're surfing the web (on Firefox and Internet Explorer only), and marks unsafe threats with red flags.
LinkScanner is also available separately as an 4MB-sized plugin for those who already use another antivirus (though check compatibility).
Sophos Antivirus for Mac
Simple to use, Sophos antivirus for Mac runs in the background while you work, scanning files for threats whenever your Mac opens them. It's had fab reviews in techie publications, but has been known to slow down some systems.
ClamXAV 2 Antivirus for Mac
ClamXAV 2 antivirus adds a user interface for Mac OSX, so it's accessible to non-techheads. Though it's free, it accepts donations towards its upkeep. It's great if you want to scan files for Windows threats before sending them onwards.
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Antivirus software isn't the only protection your computer needs. If you don't have a firewall, you're leaving all your files and sensitive information vulnerable. Effectively:
Antivirus = the border patrol checking what's allowed in.
Firewall = the fence stopping it getting there in the first place.
So why aren't we all going firewall mad? We tend to connect to the web via a router, rather than just a modem, and routers provide a hardware firewall. Make sure yours is switched on and set to a high enough security level. Consult the manual or search online for the make and model number if you don't know how to check.
While you're there, check you've changed your router password from its factory-set default. You'd be surprised how many connections are hacked (and how much havoc gets wreaked) because the standard password hasn't been changed. Spend a little time to get your settings right here, as router firewalls give a higher level of protection than software ones.
If you don't connect via a router, or you're just big on online security, here are the top freebies:
Firewalls: Free PC software downloads
Windows XP, Vista, 7 and 8 have a firewall built-in, which should be enough for most people (especially those who already have router firewalls), but make sure it's switched on and your copy of Windows is up-to-date. The firewall can be set on low, medium and high levels of protection.
If the Windows firewall is set on high, you may need to spend some time tweaking its settings in the Control Panel to stop it becoming a nuisance. By default, it'll stop you downloading files over Skype, and it'll block a whole load of programs that download from the web.
Outpost Firewall Free Edition
Agnitum's Outpost Free Edition is a good all-rounder and has a good combination of top protection and user-friendliness. It's totally free and there are no messages nagging you to buy a copy.
Comodo Personal Firewall
It's totally free but you'll need to register and activate the licence by email within 30 days of installation. While Comodo outperforms many similar offerings, it can be intrusive, especially if you just want a firewall that does its job quietly.
Firewalls: Free Mac downloads
Built-in: Mac firewall
Since the early days, all web-ready Macs have come with some sort of firewall as standard. Which yours offers depends on what version of OSX you're using. To check your settings, go to Preferences > Security.
Luckily, it's good, because as far as we can see there are no other decent free firewalls for Macs.
If you know or use any other free antivirus packages or firewall software, please share them in the forum discussion.
There are other types of malware you can find on your computer. Often legitimate developers will design programs that have useful functions, but they'll also provide the owner with useful information about you or try to sell you things.
Adware. Pop-ups that try to sell you things
Adware is malware that sneaks onto your machine and opens up pop-up windows that sell you things.
It's easy to assume these are related to the site you were visiting, yet often they aren't. If you've closed your browser, but pop-up windows still appear on your desktop, chances are you've been infected.
Spyware. It tracks what you do
Spyware is a more dangerous, less noticeable type of malware. It covertly grabs information from your PC and sends it back to its leader out in the cyber-ether.
Malicious spyware programs have become much more advanced in recent years, undoubtedly due to their potential for criminal money-making, so some of yesterday's top spyware removers can no longer cope.
Basic anti-adware/spyware measures:
To put your mind at rest, you'll need to download some extra software. In the meantime, there are a couple of basic ways to fight back:
Use a pop-up blocker
If you're being troubled by adware, use a pop-up blocker to alleviate the symptoms while you find a solution. Be aware though, that not all pop-ups are bad - some sites open new windows in this way. If you want to see them, hold down CTRL while clicking the link.
Check whether you allowed the spyware
There are a couple of legit spyware programs. Google's Desktop can send info on what you've been searching back to Google, and Alexa's toolbar can do the same. In both cases these firms want to monitor your computer to help develop their products with data about searching habits.
Whether you allow this depends on how you want the information to be used. It's mostly harmless but does mean someone, somewhere has access to your searching habits.
- Be careful when downloading
The usual way for ad/spyware programs to get on your computer is by attaching themselves to other things you download. So make sure you check the veracity of download sources before getting files.
Delete programs you don't use
Use the add/delete function on your Control Panel to get rid of any programs you don't need any more - they may be corrupted.
Like most antivirus tools, spyware removers work by comparing what's on your machine to a list of known offenders. As ever, the top anti-ad/spyware programs are commercial, but that doesn't necessarily mean you need to buy them. Try these first:
Ad/spyware removal: Free PC downloads
Ad-Aware's great at detecting and removing malware, and this new version works even faster than previous ones. On the downside, most features are locked in the free version. If you make it your primary tool, you won't be fully protected.
While the free version doesn't provide real-time protection or scheduled updates, Anti-Malware is still powerful enough to make a big difference. As a lightweight program, it's pretty quick too.
Spybot - Search & Destroy
Spybot's been going for a while, and while it has a pretty long list of features, it's always received mixed feedback. It's fairly processor-hungry, so if your computer's already slow it'll be an unwelcome addition.
Ad/spyware removal: Free Mac downloads
SecureMac's MacScan software is built to detect, isolate and remove spyware apps as well as blacklisted cookies saved on your system. It's a 30-day free trial; you'll pay $40 to upgrade if you like it. Reviews are mixed, so if it doesn't work for you, just delete it once the trial's finished.
AVG LinkScanner Mac Edition
Not really an anti-spyware tool, but AVG's LinkScanner is worth a look for Mac users. It uses real-time threat detection which checks links out when you're browsing the web (Firefox and Internet Explorer only), and marks unsafe ones with red flags so you know to avoid them.
We've all had moments of horror (even in this very office) where due to hardware failure, power cuts or just plain ol' silly mistakes, precious documents disappear. As more and more of our lives are committed to the digital domain, backing up data is becoming increasingly important. Since there are ways to do it free, you'll only have yourself to blame if you don't.
If your PC broke, what files would you miss most? These are the ones you should be backing up as a minimum.
If you'd rather keep more tangible copies of your files, the options are either storing them on CDs and DVDs (you'll need a CD/DVD writer), or on an external USB hard drive for bigger/more files. As technology marches on, the latter are getting increasingly cheap; 1TB (1,000GB) for about £50 is now the norm if you buy online.
Check out the Cheap Memory Cards guide for some top picks.
Use online storage
Online storage, or "cloud" storage services as they're also known, use a virtual hard drive that's installed on your desktop and linked directly to your online space.
There are a whole load of online storage services available, with many offering a few GB of free space. See Free Online Storage for a full list.
If you've already lost valuable files, there may still be some hope in the form of recovery programs. Freeware programs Restoration, Recuva, Puran File Recovery and PC Inspector work to recover lost files, but as you may expect, it's a lottery as to whether they actually succeed.