Sometimes you can’t trust your security software to have blocked a specific threat. If your computer is playing up, but your security tool swears blind there’s nothing wrong, you might want to get a second opinion. The problem is, you can’t just go and install another anti-virus tool, because chances are it’ll conflict with the program already on your system.

What you need to do is run an anti-malware tool that has scan-and-remove capabilities, but doesn’t offer any realtime protection. If you don’t want to install another program on your PC, try a portable option: download the program, run the scan, job done.

Microsoft Safety Scanner is one such tool – it presumably uses the same virus definitions and technologies as Microsoft’s popular Security Essentials package, albeit without any real-time protection. Just download the correct version (this is the 32-bit version, there’s also a 64-bit version available), then double-click the tool and follow the instructions. Start with a quick scan, migrating to the full scan if nothing is found and you still don’t trust the results. If any infections are found, the tool will attempt to remove them.

And that’s pretty much it. The download includes all the latest definitions at the point the program was downloaded, hence the large download size. There’s no update facility within it; instead the program will expire 10 days after downloading, forcing you to download it afresh before running it. The reasoning is sound – download a single package, perhaps on to a clean computer before transferring it across – but it’s still annoying as it means the tool can’t be downloaded and stored somewhere safe before updating and using.