The big G added another helpful feature to “Google search”,  today Google announced that from now on-wards  Google will tell you whether your PC has been infected from malware or not.

Users from malware infected computers when performed a search on Google  will notice a large yellow box on the top of the screen telling you that “Your computer appears to be infected”, if you see the message, you need to clean up the infection from your machine.

Recently Google found some unusual search traffic while performing routine maintenance on one of their data centers. After collaborating with security engineers at several companies, it determined that the computers exhibiting this behavior were infected with a particular strain of malicious software, or “malware.” As a result of this discovery, today some people will see a prominent notification at the top of their Google web search results.

This particular malware causes infected computers to send traffic to Google through a small number of intermediary servers called “proxies.” We hope that by taking steps to notify users whose traffic is coming through these proxies, we can help them update their antivirus software and remove the infections.

Google said “In case our notice doesn’t reach everyone directly, you can run a system scan on your computer yourself by following the steps in Help Center article.”

According to Matt Cutts this malware driven traffic is  specific to Windows and google is  trying this as an experiment to alert and protect consumers from malware infection.

But I have to remind you that  it is not possible for google to detect all types of viruses and malware, so its your duty to keep your computer clean.I would recommend you to use Microsoft Security Essentials which has top rated Antivirus engine and more over it is free.