1. Regularly install updates for your anti-virus software.
New viruses are constantly appearing - unless you have updated your software, it may not have the necessary information for handling new virus types and variants. When you install an update, new entries are added to the software's virus definitions database so that suspect files can be recognised and dealt with. F-Secure issues a new anti-virus update daily, and unless you change the settings, will remind you every seven days that you should update.- normally, every couple of weeks should be considered the longest you should leave it. Make a special effort to update when a new virus "hits the headlines".

2. Think twice about using Outlook Express for your e-mail.
Outlook Express is too closely bound up in its workings with Internet Explorer and your access to the World Wide Web to maintain adequate security. Using more self-contained e-mail client* software, it's pretty well impossible for a virus to enter your computer except through your opening an infected attachment. With Outlook Express, simply through an e-mail being displayed in the Preview Pane you can be taken straight to a website from which infected script is loaded up on your computer. A patch has been issued by Microsoft to deal with this glaring security hole, but this has been severely criticised by independent evaluators. For more information, click here. It's much better to use fully-fledged e-mail client software, such as plain Outlook, First Class Conference etc. for handling your e-mail.

* The client-server relationship is something which you'll keep coming up against when you use Internet services - your computer needs the appropriate client software installed so you can use the services of particular types of server - e-mail, ftp (file transfer protocol), web. A server is just a "dedicated" computer - one which serves a specific purpose in a network.

3. Don't open e-mail attachments unless you know who's sent them and what they are. Change your view settings so you can see file extensions.
This is much more important with some types of file than with others - you can recognise different file types by the extensions they have. .EXE, .COM, .PIF, .JS, .VBS, .SHS, .SCR, .DOT are some of the most notably dangerous. Double file extensions - for example "readme.txt.vbs" - should always be treated with suspicion.
Look out also for oddities in the header information of e-mail messages - a sender you've never heard with a subject such as "sorry about yesterday"; a blank subject header.

On many computers, the default setting means that you see file names without their extensions. So, suspect attachments won't be immediately evident. To set your computer so that you see file extensions:open My Computer or Windows Explorer. From the View menu, select Options, then click the View tab. Make sure that "Hide file extensions for known file types" isn't checked.

4. Never leave a floppy disk in the drive when you start up or restart your computer.
This is the standard, old-fashioned pre-Internet way of passing on viruses. By default, your computer looks first for its operating system to the floppy disk drive, and only then to the hard disk. So, if an infected diskette is on the drive, off goes the virus when you boot up. Always reformat old disks before you reuse them. A virus may have been lurking on it for years. If you have the confidence to change your computer's BIOS settings, it's a good idea to alter the boot sequence to C: A: This will set your computer so that it refers first to the hard disk instead of the floppy drive when it boots up.

5. CDs and Zip disks can carry viruses too.
Now that Internet-transmitted viruses are far more popular than disk-transmitted ones, this isn't all that common. But it remains a possibility! You can run an anti-virus scan on any kind of diskette - this never does any harm.

6. If your anti-virus software reports a suspect file, take all possible action before you close down your computer.
Familiarise yourself in advance with your anti-virus software so that you know what decisions to make in an emergency. It's at the stage of booting up again that a virus file can pass all of its nastinesses into your operating system, and into your system registry.

Whatever anti-virus software you're using, you're likely to run into situations where a file is recognised as suspect, but contains a new or unusual virus which isn't included in the software's virus definitions database. If this happens you will be told that the suspect file can't be disinfected, and offered the choice to rename or delete it. Delete unless you have very good reasons for thinking it could be a wanted and important file.

F-Secure users in this situation may find it something other than intuitive that you must press the Back button to return to the screen where, when disinfect has failed, you can choose the delete or rename alternative. Don't press the Finish button!!

7. Make sure you have a system start-up disk to use in emergencies.
If a virus does manage to infect your system, it could mean that you can't load Windows. Without a start-up disk, which will be different for different computer models and operating systems, you - or anybody you call on for help - will have a much harder time rescuing your system in the event of failure. This applies whether or not failure is due to a virus infection. If a start-up disk wasn't supplied with your computer, follow the appropriate link (Internet connection required) to Microsoft's instructions for making one: Windows 95/98 ;Windows ME; Windows 2000; Windows XP.

8. When using Microsoft software, always make sure that you keep macro virus protection enabled.
Macros are stored sets of instructions which are used within Microsoft Office applications to automate complex or repetitive tasks. Unfortunately macros can also be used to introduce viruses. Macro virus protection is set from within each of the Office software applications:
Office 97: from the Tools menu, select Options, then General. By default protection is enabled - don't switch it off!
Office 2000/XP: go to Tools | Options | Security. With Macro security set to medium, Word warns of macros in a file and prompts whether you want to disable them. High security automatically disables all "unsigned" macros.

If you receive a macro warning when you open a Microsoft Office file, always select the "disable macros" option unless you expect the file to contain a macro and know that you can trust it.

9. Only download files from trustworthy websites.
Always avoid downloading files from bulletin boards or public newsgroups - these are particularly likely to be used by virus writers to distribute their new viruses. When downloading software updates (for instance drivers, multimedia players etc.), go to the manufacturer's official website. Be watchful!

10. Never pass on a virus warning without checking first yourself that it isn't a hoax.
Hoax virus warnings can be more than just a nuisance - they may be almost as dangerous as viruses themselves. For example, you may be instructed to delete a file from your computer in order to prevent a virus infection, when in fact the file is an essential system file. Before passing on any virus warning message, check on the specific virus you're being warned about at the F-secure website, or the website of any other producer of reputable anti-virus software.