Updates automatically downloading though set to manual

Hi all. I have Windows Updates set to notify me when updates are available but allow me to decide when to download them. In spite of this, sometimes updates automatically install if I don't do it right away. For example, I receive a notice that updates are available but I'm in the middle of something else and I wait an hour or two before attempting to download them. When I go back to the updates they've already been downloaded and installed even though I'm sure I didn't click anything to start the download. But it doesn't do it with all the updates. I'm not sure but I think it's doing it with Windows Defender and maybe some other security related updates. I DON'T have Defender set to check for updates before an automatic scan. I don't have automatic scanning turned on even.

Anyone else ever seen this or know what might be causing it? I have Vista Home Basic 32bit. Appreciate it. :D

Some updates will always be on automatic
Those for SecurityEessentials for example or Defender and some that are urgent.

Hi Rich. I thought the whole point was to notify me and then let me decide when and if to download. If it's gonna do it automatically anyway I guess I'll just turn it off completely. Thanks for the info, at least I know there's nothing wrong with my system. :D