The following review written by one of the Software Informer contributors applies to version 2.5
In the past, one of the most common methods used by viruses and malware to infect computers was through portable devices like flash drives and USB sticks. By default, the autorun files specific to these devices were automatically loaded by the system, facilitating the spreading of viruses and malware; and many security applications have been created specifically to deal with this type of infection.
USB Guardian is one of them.
USB Guardian continuously monitors the system, detects when a portable flash drive is connected and immediately locks the suspicious files from the device. This way, the connected portable device can be used as you need and the risk of infecting your computer is minimal.
Anyway, compared to many other tools that do pretty much the same job, USB Guardian fails to impress. On the contrary, it annoyed me considerably by compelling me to install a toolbar that also changed the homepage and the search engine of my browser. Usually, ad-supported tools like this one only ask you to install such additional software, but that’s not the case with USB Guardian: it would completely halt its own installation until you accept installing the toolbar too. There are some advantages, like the neat interface, but they can’t compensate for this important downside; so my opinion is that you should look for a different tool than this one if you want to protect your computer against this kind of threats, especially since there are plenty of such applications on the market.