I think whether you load both or just one depends on your computer needs.

The Grimefighter is Avast's tool to clean up useless or unwanted add-ons, etc from your computer system. If your computer is very slow...you might need to run the Grimefighter. But, personally, I tend to stay away from these types of programs because they often clean up more than you want them to. Unless you have a serious need for this...I wouldn't recommend it.

However...if you just need an antivirus program...Avast itself is what you're looking for. Another good antivirus program that seems to be quite popular with many gurus here is AVG. I, currently, don't have either but did use AVG at one time. It's a good program. I can't give testimony regarding Avast due to my own lack of experience with it.

Anne