Tomorrow is, as we’ve been told over and over by the tech press, release day for Windows 10, and I’m sure we’re all looking forward to discovering our Windows 7 and 8 machines have been upgraded.

No, of course we’re not. I think we’d all be rather peeved to learn that our OS was changed without being given the opportunity to say “No, wait! I’m not ready!” And Microsoft is smart enough to recognize that. The upgrade will be pushed out to computers that have requested it, but it won’t be installed until the users give the OK.

Good thinking, Microsoft. But apparently there’s a bit of a left hand/right hand disconnect in Redmond.

Y’see, once we install that upgrade, we* lose the ability to control future updates. Since at least XP, Microsoft has allowed users to choose which updates to install and when to install them. It hasn’t always been easy to find the “Download updates but let me choose whether to install them” selection, but it’s been there. Apparently it won’t be there in Windows 10.

* In this context “we” are anybody who has an individual Windows license. The rules will be slightly different for business customers. But if you bought Windows directly from Microsoft–including getting the free upgrade–or had it pre-installed on your new computer, you’re part of the “we” even if you get Windows 10 Professional**.

** Win Pro users will be able to turn off automatic updating and defer updates indefinitely, but if they haven’t installed all updates, they don’t get support from Microsoft. Got a glitch that forces you to call Microsoft to reactivate Windows? Better hope you’ve installed all updates.

In some respects, this is a GoodThing. Quickly getting security updates onto millions of machines is, on the whole, a desirable thing. There’s an obvious analogy here to requiring kids to be vaccinated before they can attend school. (The computing equivalent of children who shouldn’t be vaccinated would be those “high-availability” corporate servers and the like, where the owners have to be able to control exactly what and when updates are installed.)

But Microsoft won’t just be installing security updates. Windows Update will also deliver driver updates. I’ve had a few network cards disabled by an updated driver delivered by Windows Update. I don’t anticipate Windows 10 will be totally free of bad drivers and driver conflicts. Though I suppose if Windows Update kills my network, I don’t need to worry about getting any further updates.

And don’t forget that Windows 10 will get significant feature updates, totally new functionality, delivered via Windows Update too. Fortunately, Microsoft never has bugs in new features, right? OK, maybe that’s a tiny bit optimistic.

Bottom line, being able to control updates meant we could hold off installing them for a few days to check early reports of problems and even opt-out of troublesome updates.

Delaying updates will still be possible, at least for a “limited” amount of time–although there’s no word on how long “limited” is. (Hours? Days?) And Paul Thurrott points out that one of the first updates Microsoft will be pushing out is a functional update to allow users to “hide” updates so they won’t be installed. So it seems Microsoft is backing away from a fully automatic update process–but Thurrott’s screenshots of the “hide” UI shows that Microsoft doesn’t intend you to permanently hide any updates. The exact text is “…if an update isn’t working you can temporarily hide it.” Hopefully by the time “temporarily” expires, it’ll be working.

If not, well, maybe you can roll it back. Thurrott also points out that you can use System Restore to restore your OS to the state it was in before the update was installed. Of course, first you have to turn on System Restore, since Microsoft decided to disable it by default. But you can turn it on (at least for now), roll back any updates you don’t like, and hide them so they won’t be reinstalled. Kinda like playing Whac-A-Mole with your computer.

One final thought: significant updates are still going to require a reboot. One of the things that I loathed about my PS3 was that it frequently required me to install an OS update–with reboot–before I could play any game, and then when I put the game disc in, it would make me wait while it downloaded patches for the game. I often had to wait half an hour or more before I could start playing a game. If Windows 10 forces me to install an update and reboot without giving me the opportunity to defer the reboot until I’m ready without constantly nagging me to reboot, I’ll be reverting to my Windows 7 and 8 backups.

You were going to do a full backup before you installed Windows 10, right?