If I make a backup beacuse I am missing files in mybb, Where would I upload them to my new copy of mybb?
You need to describe your problem a bit clearer, it's hard to interpret.
Not that hard. Make a backup where would I upload it for my new copy of mybb?
What you're saying is you want to make a backup, then re-upload it? I don't see a point nor can I still interpret the question because you didn't really re-phrase it at all.
All right then. I am missing my Images files so I can't upload themes or anything. So I was told to get a new copy. So where would I upload my backup so I don't need to get all my users again.
Oh. Just backup the database, re-upload the NEW MyBB files, but don't use the installer. Import the old database backup to the new MyBB corresponding database.