You could use CCleaner.
Last time I checked, CCleaner wasn't a AV.
Also, about the norton thing, unless you always go on high risk sites or stuff (which you should only be doing with a VM or and sandboxie style program, chances are you won't end up with a nasty virus. I still recommend webroot and malwarebytes are secondary layers of protection either as a secondary scanner or AV, since they don't eat up much resources on your computer assuming you own a more recent PC.
If anyone's especially scared about getting viruses and fears their AV just won't cut it, you can block all .exe's from executing in the appdata. (this obviously can block legitimate exe's too, but you can make exceptions too. remember this is no where near a replacement for a AV program nor a significant safety layer as this only blocks certain viruses).
how to block exe's from executing in appdata