This isn't going to be much help but its the only way to avoid viruses and fix your problems.
My advice is to copy your data, photos, emails, documents and music you have off the pc, reformat and re-install windows and all drivers and plugins.
If people persist with using windows they need to know how to do this its not that hard and many guides can be found online. If you keep using windows you will need to do this regularly anyway so best to learn how to do it just dont tell your friends or you will end up doing it for all of them.
After this never use IE, use Chrome it is far superior in every way to any other browser and reduces the chance of viruses exponentially. Switch from client based email to gmail and never run executible files that are emailed to you unless you absolutly know what they are. Keep your kids off the computer as they wont follow any of these rules and will download and install all sorts of rubbish.
I know its not much help but it really is the only fix these viruses corrupt files and the effort involed in finding, removing and replacing is to much when a simple format and re-install can fix it in a couple of hours.