I use TweakUI to disable AutoPlay as I hate it with a passion. But anyway.... after reading the instructions in the link below and checking the appropriate registry entry, it seems AutoRun was already disabled for this PC, maybe as a result of disabling that annoying "feature" called AutoPlay, but it also seems AutoRun can be disabled independently (at least that's the way I read it) while leaving AutoPlay active and continuing to treat you like a two year old with a learning disability.
Did I mention my dislike of AutoPlay.
How to disable the Autorun functionality in Windows
The article mentions a Windows update (or two) which needs to be installed for AutoRun to be disabled. I'd be willing to bet though, if you already have the "NoDriveTypeAutoRun" registry entry the article refers to, you'd already have the necessary updates installed. I'd imagine after changing the registry entry a reboot would be required.
Please report back as to whether it works.