First, you have to start using Linux.

Second, you need to stop downloading anything that is microsoft related.

Files with endings like avi, wmv can send you to a web site without knowing it and microsoft is the one who put this into the format.

Think about why you would need to send people unknowingly to a web site when playing a movie or sound file.

There is no reason. Except to support spammers and spread viruses.

So microsoft supports spammers and the spreading of viruses and they should be banned off the planet.

If you stop downloading those files, people will stop sharing them.

If you know how to convert files to a safe format like mpg or ogg then please do so.