make sure you have not one single instance of unauthorized music on your machine. That includes music you ripped from your CD collection.
That isn't illegal to rip music from your own CD collection. You are able to make copies of your own collection, it is only allowing others access to copies of your collection that it becomes illegal, doesn't matter if you got paid or not for it.
Same thing goes with software. You are able to make a copy of said software as a backup as long as it is a backup for your own use not to sell or give to someone else.
There is a significant difference of making copies as backups for your own use, compared to making copies for someone else's use.
It's that intent to distribute is where they get you.
If making copies of anything that you don't own the exclusive rights too is illegal, then think of everyone that is breaking the law when they backup their hard drives to make sure that they have backups. Fonts, software, vector images that they received from the owners in order to do print jobs etc.
It's the intent to distribute that is the illegal action. Doesn't matter if it's for profit, but that you distributed it to other people.
And make sure you do not have one single instance of some avatar you downed from the internet.
Depends on the avatar. Some avatars are given freely from people that own the rights for you to use as an avatar. It might be better to say "a single questionable instance" or something like that. There are instances to where people that own rights to pictures that give other people free access to use those pictures as wallpaper, avatars etc.