Protecting personal details Complete giveaway

Be wary of entering personal details on computers in internet cafes or libraries

Internet Explorer also has an AutoComplete feature for filling in online form fields. This is handy, but can allow others using your PC to view your usernames and passwords.

To change the AutoComplete settings go to Tools > Internet options > Content tab. Click AutoComplete, and you'll see an option to switch the feature on or off for web addresses, forms and usernames and passwords.

Changing browser settings is simpler in Firefox (www.mozilla.com/firefox). To clear cached webpages, cookies, saved passwords and form details:

Go to Tools > Options > Privacy. Click the relevant + symbol to view options for each. To remove all the information your browser has stored, click Clear all.

Under the Cookies menu, you can delete all cookies or remove them individually. You can also allow and block cookies from specific websites. To do this, click Exceptions.

Spyware savvy

A further security threat is posed by spyware – malicious programs that install themselves without your knowledge in order to track your web use or record passwords as you type them in online, for example. Pop-up ads are a common breeding ground for spyware. Thankfully both Internet Explorer and Firefox include built-in pop-up blockers.

In Internet Explorer, go to Tools > Pop-up blocker > Pop-up blocker settings, where you can specify sites you don't want blocked. In Firefox, go to Tools > Options > Web features to control the pop-up blocker.

Watch the Which? video guide to protecting your PC from spyware.

Need help understanding computer security jargon? See our free guide to understanding PC security terms.

Password protection

Making passwords difficult for criminals to guess is an easy way to tighten security; all too often one simple password unlocks your whole life. The trick is to choose passwords that are easy to remember but difficult for others to guess - try mixing letters and numbers or making an acronym from a favourite song, say.

If you have too many passwords to remember, a password manager like the one built into Firefox can be a good idea. To remove or view passwords using it:

Go to Tools > Options > Privacy > Saved passwords > View Saved Passwords.

You can also set a Master Password that will be required in order to retrieve any stored passwords each time you use the Web - just make sure you don't forget it!

For more on online security, see our book Internet Made Easy for the Over 50s.