How can I use Windows XP safely now it's no longer supported?

A screen showing the countdown to the end of support for Windows XP. Photograph: Jorge Sanz/Demotix/Corbis

My bet is that the vast majority of the Windows XP users reading this did not update their computers/operating systems by 8 April. What actions should they take to minimise their exposure to attack, while they consider their options/save up? Whitesocks

Microsoft has shipped its final update for Windows XP, which means all the new security holes will not be patched. Nobody knows what will happen next, but malware writers are expected to target the remaining machines. If you are still running Windows XP, it would be a good idea to make it as secure as possible. Unfortunately, there is no 'magic bullet'. The things you can do to protect XP apply to all versions of Windows. However, because XP will now get more insecure every month, you need to take protection much more seriously.

It's a huge problem. There are roughly 1.5 billion PCs in the world, and NetMarketShare reckons that 27.7% are still running XP. That's more than 400 million machines. Since XP is fundamentally much less secure than Windows 7 (48.8%), Windows 8 (11.3%) or even Vista (3.0%), it's a very attractive target for malware writers. (For comparison, all versions of Mac OS X add up to 7.6%, with Linux at 1.5%.)

The quickest way to make a Windows XP machine almost completely secure is to prevent it from accessing the internet. This works for some business PCs that are used for specific purposes, such as controlling machine tools, but isn't practical for most users. However, an alternative is to install a copy of Linux on the same PC, or boot Linux from a Live CD, and use that for browsing and email. Dual-booting two operating systems is tedious and time consuming, but at least you can get online while continuing to use the XP software that has presumably prevented you from upgrading to a more recent version of Windows.

Microsoft's solution was to provide an XP Mode in Windows 7 Pro. This let you run Windows 7 as your main operating system, while simultaneously running a free 'virtual' copy of Windows XP. The price of Windows 7 Pro means this isn't a solution for most home users: you'd be better off putting the money towards a newer -- perhaps secondhand - PC.

So, let's look at what you can do to run an XP machine normally, but more safely.

Protecting XP on the net

The quickest and simplest way to make XP more secure on the internet is to use it from a limited account. Most people use 'administrator' accounts, because these let you do whatever you like. The problem is that any malware that gets control of your admin account can also do whatever it likes. The solution is to use a 'limited' account, which also limits what most malware programs can do.

Of course, if you need to install some software or make system changes, you will have to switch to an admin account. To make this a little more palatable, tick the box that says 'Use Fast User Switching' when you set up the limited account. If children or accident-prone adults share the same PC, they should definitely be given their own limited accounts.

All XP accounts should be protected by passwords, though many people don't do this.

You should also download and use a more secure browser than Internet Explorer 6, 7, or 8. Microsoft has chosen not to provide its own more secure browsers, IE10 and IE11, to XP users, at some sacrifice in market share. However, there are several alternatives including Mozilla Firefox and Google Chrome. Generally, I prefer Firefox, as it consumes far fewer resources than Chrome, handles more tabs, and doesn't crash as often. Against that, Chrome is probably more secure because its 'sandbox' means malware writers need two exploits to penetrate it: one for Chrome and another to get out of the sandbox.

When you have installed Firefox, Chrome or Opera, add a browser extension called HTTPS Everywhere. The 'S' indicates that it uses encrypted communications to talk to websites, whenever possible. Its main purpose it to improve privacy, but it also makes browsing more secure.

Finally, for this section, be careful where you go. Most commercial sites tend to be safe, but sites that offer free stuff - pirated music, movies and software, wallpapers etc - either may not be professionally run or may be making their money by other means. Websites can make a lot of money from 'drive by' installations of advertising programs and other unwanted software.

Keeping software up to date

You will no longer be able to update Windows XP, but that makes it even more important to keep all your other programs up to date. In my experience, the simplest way to do this is to run Secunia's free Personal Software Inspector (PSI) to check for and install updates. In particular, make sure you keep Adobe Flash, Adobe Acrobat and Oracle's Java up to date, as these have poor security records. Best of all, uninstall all versions of Java completely, and see if you can manage without it. If not, you can always install the latest version when you need it. (Java has nothing to do with the browser scripting language, JavaScript.)

Indeed, it's a good idea to run the Add/Remove Programs utility and a utility such as SlimCleaner to see if you can remove any other software you don't need. The fewer programs you have, the fewer things there are to attack.

Many people update their browsers and desktop software, but completely forget about updating their browser plug-ins. This is dangerous because Flash, Java and similar plugins are in the front line. You should therefore visit Mozilla's Check Your Plugins page. This also provides trusted links to the newer versions that need to be installed. Qualys also offers a browser-checking site. The option to 'Scan without installing plugin' is quick but not as thorough as the plugin version.

Again, uninstall any plugins you don't need. This will make your browser slightly more secure, and it will probably run faster.

Note that Microsoft has also stopped supporting Office 2003, and this is now vulnerable software. If possible, upgrade to a more recent version. If you aren't willing to pay the (very reasonable) price, you can use the free but less powerful online Office web apps that are part of Microsoft's free OneDrive cloud storage. If you only need to read or create relatively simple documents, the free and open source LibreOffice may be a viable alternative.

If there's a program you can't either update or replace, you can run it in a protected sandbox by using another free program called Sandboxie. You could also use it to protect your browser or social networking programs. However, only the Pro version (€15 per year) lets you run multiple sandboxes at the same time.

Security software

If you are still going to use Windows XP, you should also beef up your anti-malware software. While Microsoft will keep updating Microsoft Security Essentials, you should either replace that with something stronger or add extra protection by using Malwarebytes Anti-Malware. There are plenty of free replacements: see the Best Free Antivirus Software section at Tech Support Alert (aka Gizmo's). If you are willing to pay for an anti-virus suite, Kaspersky Internet Security 2014 and Bitdefender Total Security 2014 are worth a look.

If you're not buying a suite, it's also worth replacing Windows XP's firewall. Again, Tech Support Alert has a useful guide to the main options. For XP, I'd suggest the Comodo Firewall with the Maximum Proactive Defense feature installed. It uses a Host Intrusion Prevention System (HIPS) that tries to stop malware from working by monitoring its behaviour. There will be an annoying period where you have to tell it which things are safe, but extreme suspicion is justified in an unsupported operating system.

Finally, for this section, there are now programs that monitor and/or analyse websites and block ones that might be malicious. They also help to protect you from phishing attacks and clickjacking. You can't use Microsoft's SmartScreen filter, which is included with IE10 and IE11 and built into Windows 8. However, Web of Trust is a community-based substitute. The new Malwarebytes Anti-Malware Premium ($24.95 per year for three PCs) also does some ferocious site blocking.

It remains to be seen whether all of this will be enough to protect Windows XP in the long term. It will certainly make your online experience more annoying. That's part of the price of using unsupported software in a world where most of us do online shopping and banking, where malware can encrypt your hard drive and hold your PC to ransom, and where identity theft can have devastating consequences.

Frankly, it would be better to buy an upgrade to Windows 7 or Windows 8 - now that 8.1 Update 1 deals with the vast majority of complaints about the original version - or install a version of Linux. Update 1, released on 8 April, also runs in less memory (it can run on tablets with only 1GB) so it should also work better even on older PCs.

Note: I've adapted this question from a whitesocks comment rather than the usual email to Ask Jack. With around 400m PCs running XP, I felt the topic was too important to ignore.