A House of Lords select committee recently branded the internet a lawless "Wild West". Users must guard against viruses, "spyware" – which allows crooks to access your data or even hijack and use your computer – and a plethora of scams. With a little research, however, keeping safe online is straightforward and free. Here is Times Money's guide to protecting your pc:

Upgrade your system

The newest version of an operating system is the safest. Windows users with ancient hardware should upgrade to Windows Vista or Windows XP with Service Pack 2. It may be more cost-effective to buy a new computer with this included. All users should download free security updates at www.windowsupdate.com. Set your PC to download them automatically by navigating to "control panel", then "system", then "automatic updates". You should also download the latest version of Internet Explorer or Firefox, which offer some built-in virus protection.

Get a firewall

Mircrosoft gives Windows users a free "firewall", which is an adequate first line of defence for most. This keeps out bad hackers, some viruses and some spyware. Go to "control panel" then "security centre" to activate it.

Use anti-virus and anti-sypyware software

Most new PCs come with a free trial of Symantec's Norton AntiVirus. Updates cost around £20 a year when this ends. However, Andrew Ferguson, of Thinkbroadband.com, the specialist website, says that free alternatives such as Grisoft's AFG, available for download at free.grisoft.com, are adequate. Once virus protection is in place, you must tackle spyware. Microsoft's free Defender software should suffice. Look for this in your PC's "all programmes" folder. If it is not there, go to www.microsoft.com/download for a free copy. You should set all anti-virus and anti-spyware software to receive "automatic updates". User feedback on security products can be found here.

Secure your wireless network

If you have a WiFi, or wireless, network, secure it by switching on the built-in encryption, renaming the network and switching on "MAC filtering" to restrict access to trusted computers. Get Safe Online, a Government website, has detailed guidance here.

Back-up your data

However well-protected your PC, it is important to back up your data to CD or DVD at regular intervals. This means that you will not lose important files if your computer is stolen or damaged. Keep these discs, as well as the operating system discs which came with your computer and any software discs, in a safe place away from your terminal. For more advice on how to back up your data, click here.

Be savvy

The precautions above should be combined with common sense. You should keep your PC in a secure location – not by an exposed ground-floor window, for example. And once online, be wary of scam emails. If something sounds too good to be true, it is. Likewise, avoid giving out personal details which could facilitate burglary or identity fraud. When you must disclose your address and credit card details to make a purchase, do so over a secure server at a trusted website. Avoiding pornography and offensive material should be straightforward. If you do stumble across content you believe to be illegal, however, report it here. And if your PC is used by children, read these safety tips.

If things go wrong

All PCs connected to the internet are vulnerable to viruses and spyware. These can cause numerous problems, including a general slow-down, or failure, of your system. Firewalls and anti-virus and anti-spyware software cut the risk but cannot remove it. If you suspect your computer is infected, follow this advice or, for £70-plus, call a geek on a scooter to fix it.

See the Metropolitan Police website for advice on reporting internet crime. Be aware, however, that British investigators have no authority to pursue most scammers based overseas. Scambaiting offers some consolation.

Five features

Cyber crime: bigger than drugs and aimed at you
Protect your software for nothing
Secure your WiFi
Be on your guard
Make your tired old PC run like new

Five news stories

Banks let us down on fraud protection
Websites sell bank data and Pins
Careless Facebook users open to identity theft
Cybergang raises fear of new crimewave
Digital mafia threatens internet integrity

More Times articles on the subject

Five websites

Get Safe Online
Think Broadband
Think U Know
Microsoft Security at Home
419 Eater

Five videos

What can go wrong?
Why secure your WiFi network?
The Mac perspective
Scamming the scammers
Is your son a computer hacker?

Explore Money

• Property & Mortgages

• Savings

• Borrowing

• Investment

• Funds

• Insurance

• Consumer Affairs

• Tax

• Pensions

• Broadband

Times Recommends

• How to find a good tradesman
• How to join the internet vigilantes
• Five ways the banks fleece us