Many Windows users are receiving messages about their virus scanners expiring, as regular listeners and subscribers know, we are not fans of Norton and McAfee Anti Virus and we recommend installing alternative programs that are more effective at catching malware and less demanding on the computer system. Two that meet the bill are AVG anti-virus and the Sygate Personal Firewall.

But uninstalling antivirus and spyware programs have their own risks, no unprotected computer should be exposed to the Internet. Similarly, it's dangerous to receive emails or browse until your system is fully up to date. So it's important to take care when removing the old program and installing a new one.

1. Create a restore point. Before starting, make sure you've created a restore point so you can undo things if they go wrong. Microsoft have instructions on their website explaining how to use the System Restore feature.

2. Backup your data. Before you do anything on your system you should always make a copy of your important data.

3. Get the new programs. If you are downloading the new programs, do it now. Otherwise go to your local computer store and buy the new software.

4. Read the manual. Read the instructions on uninstalling the old software and installing the new software. If you don't have a manual, visit the vendor's website and have a look at their support pages. While reading manuals is a radical idea for computer users, it might save you many hours of grief.

5. Disconnect from the Internet. Make sure you are disconnected, by logging out and pulling out the phone line, usb or network cable that connects your computer.

6. Uninstall the old software. Go to the Control Panel, open Add/Remove programs and uninstall the old program. If the uninstall instructions are different, follow them. You will probably be asked to reboot the computer, even if you aren't prompted to do so, you should anyway.

7. Install the new software. Once all the old programs are removed, install the new packages. Again, follow the instructions. If you are asked to go online to register or update the system, skip that step until you reconnect to the Internet.

   If you are using Norton Antivirus, we recommend running the Norton Removal Tool after uninstalling the product. We would also recommend reinstalling the Windows Scripting Host. If you do run the Norton tool, be aware that other Symantec products such as Norton Utilities, Ghost and versions of ACT! and Winfax may also be affected.

8. Reconnect the computer. After you have restarted, reconnect to the Internet. Do not surf the net or check your email until you have run the update programs for your anti-virus. Again, you might have to reboot a couple of times.