A virus cleaner is a device that removes all traces of the virus, and can also be used to remove virus fragments.
A virus cleaner will only clean your computer and any USB devices attached to it, and will not remove any virus that has already been created.
It is very effective at cleaning up virus infections, however, and should be used with caution.
A virus cleaner is also recommended for people with weakened immune systems, such as those who are HIV positive or who have recently tested negative for HIV.
Read more about the types of viruses and virus cleaners on the BBC.