hehe--You sound worried, Keith, since you've asked the same question again.
Audio Units are for Macs, VSTs are for PCs. As I said, when I've installed the various Garritan libraries, I've always skipped the AU versions since they won't do anything on my Windows PC. Users are given a choice between VST, AU and RTAS for Pro Tools. They are duplicates of the same sounds, programmed for the different systems.
There are VSTs for Mac, but always labelled MAC so users know which will work on their computer.
If you somehow gum up the works deleting files, re-installing of course is an option.
But right now you have duplicate versions of the same Garritan instruments.