Ubuntu displays a variety of pop-up windows (including keyring manager, update manager, upgrading windows, etc.). I would like to not have any pop-ups on my screen. Is there a general way to disable all of them?
Well I think this should disable the annoying update pop-up:
Regarding the previous answer (and in particular the "Updates are important." comment), there are many MANY reasons for wanting to disable intrusive applications. I hardly think it is necessary to lecture the Op. As an example: I for one find this update pop-up very annoying on my mythtv set-up as it not only blocks the screen but is modal.
"popups" is not a general class of application, so no, there is no general way to prohibit applications from displaying windows when necessary.
Updates are important. That is why they are being shown. There is no configuration option to neglect security. However, you can configure it to automatically install updates if you want to. You do that in Software Center. You'll find it in Edit > Software Sources > Updates.
Similarly, the keyring must be unlocked for you to use passwords stored in the keyring. The primary keyring should be unlocked automatically on login, and won't be displayed. If you have other keyrings, then you'll need to unlock them before you can use them.
I don't know what you mean by "upgrading windows".