When using Google search in Google Chrome the usual list of search results appears. However, when I click on one of the results it does not open the nominated website but instead directs me to some other website which displays either a blank page or shows me search results from a different search engine. If I complete the same search using Google through Internet Explorer when I click one of the search results I am directed to a website which again shows a blank screen. This behaviour started several weeks ago (with no obvious reason for its occurrence) and a scan of the computer using my antivirus product shows no indication of a virus. The computer is running Windows XP.

As the problem being encountered does redirect you to different websites, when you are trying to visit a particular site from search engine results, it is indicative of some kind of malware being installed on your computer. Virus scanners are generally quite good at detecting viruses, but depending on the antivirus software installed on your computer it may not be as good at detecting other types of malware, particularly adware. Generally when your internet browser or search results are hijacked, this is due to adware being installed on your computer which tries to redirect your internet browsing towards advertisements. That said, you have mentioned that in many cases you are just redirected towards a blank page. This is likely because the website to which you were redirected previously had content, but has since been closed-down but the malware installed on your computer is still pointing towards that old website. In any case, we need to investigate how we can detect and check whether any malware or adware has been installed, and then subsequently remove the relevant threats from the computer.

You should first download and install Ad-Aware Free (www.lavasoft.com), Spybot Search & Destroy (www.safer-networking.org), and Windows Defender (www.microsoft.com/downloads) onto your computer. Between these three utilities most threats should be detectable and removable. Scan your computer using each utility individually, removing any identified threats. After you have completed a pass with each utility restart the computer and then do another pass, to make sure that everything has been detected and removed.

However, you may find yourself in the situation where you cannot completely remove the problem from the computer using these utilities. This is more of a problematic situation since without having someone experienced looking at the computer and various files, to determine the source of the problem, it will be difficult to remove. Furthermore, you may have read from my previous columns that I am a fairly strong believer that once a computer has been compromised with a virus or malware, that computer can never be trusted again since you cannot be 100% certain that all of the threats have been removed. This is why I am very careful about the software which is installed on my computer and recommend that whenever a computer is compromised that the best solution is to backup all data and complete a clean reinstallation of Windows.

Whenever a clean reinstallation of Windows is recommended some people tend to think that it’s a bit heavy-handed. By no means is the reinstallation of Windows a trivial process, but when the computer has been compromised I tend to take extra precautions since most people use their computer for sensitive transactions (such as internet banking, online shopping) and having doubts about whether the computer is secure is not a good thing. There are things which you can do as part of your usual computer maintenance to alleviate the burden of having to reinstall Windows. The best suggestion is to make sure that you regularly backup the computer. My recommended setup is having an external USB hard drive always connected to the computer and then running an automated backup. You will likely need to investigate third-party utilities for this purpose, but there are plenty available such as Acronis True Image Home (www.acronis.com.au/homecomputing/products/trueimage) which are both relatively affordable and do quite a good job. However, I would strongly encourage you to look at other options to find a backup solution which meets your needs. Regardless of the particular software which you choose, having a regular backup will make sure that you can easily recover your data should a reinstallation be necessary due to the computer being compromised or perhaps due to software corruption or a hardware fault.

It is also worthwhile mentioning that if you do not currently have an adequate antivirus package installed on your computer, or you are not satisfied with the performance of the antivirus product, that Microsoft offers a free security suite called Microsoft Security Essentials which includes both antivirus and anti-malware protection. Additionally, it has a small footprint so it doesn’t consume a huge amount of system resources. This is in contrast with many other antivirus products which are currently on the market that have quite a negative impact on system performance. You can download Microsoft Security Essentials from www.microsoft.com/security_essentials .