The keys should be in this location
HKEY_Local_Machine - System - CurrentControlSet - Enum - USB - Root_Hub
But if you found them somewhere else, don't worry about it too much. Just make a backup copy of the registry, like you should always do before modifying the registry. Go to file - Export, and give it a name, place it somewhere that you can find it if needed.
Now, when you click on any of those USB VID keys, on the right side of the window, it will list details about that particular key. It should say whether it's for a printer, a scanner, or the Host Controller.
You can usually delete all those USB VID keys with no problems, they should reload when you restart windows. BUT, if you have a USB mouse or keyboard, that can create some problems if you need to log back into Windows.