A few additional suggestions:
First, teaching your husband to be more careful would be a good idea. Preventing is much easier than removing viruses.
Second, as USB sticks can often transfer viruses between computers, it would also be a good idea to be sure that the "autrun" feature of the USB stick is disabled. Right click on it, go to Properties, Autoplay, and be sure it is always set to "Prompt" for each of the different type of files in the pull down menu. That will prevent a virus from automatically running when you insert the USB stick into your computer.
Third, when you do insert the USB stick, be sure to ALWAYS right click and scan it before opening or running anything.
Fourth, you did the right thing to always move them to the chest (quarantine) rather than deleting them. That is because sometimes you need to know what the virus is to be able to be sure that it is completey removed. If you just delete it, it will make it harder for anyone to help you.