Is there anyway to stop Windows 8 from restarting for an update?

This answer may be incomplete for current Windows builds

Windows has something called UpdateOrchestrator that runs a one-off task that will reboot as needed by servicing. Windows seems to repair this task when users try to nullify it, but borking permissions on the task's file seems to be a rational solution, and may now also be a requirement to prevent automatic restarts.

^{I had a machine spend a week analyzing a destroyed NAS RAID5 array across four 4 TB disks. It completed successfully and was ready to do recovery. I let the program sit there while I prepared to assemble the target resources. It automatically restarted while idling here.}

Original answer follows.

Updates are always welcomed, and I like to think in software as complex as the likes of Windows NT indicate good health, or at least the desire for resilience. So I say assume good faith in claims of urgency. But if they're destroying your work, here's some Group Policy that considers your situation.

Tested solution in upper-segment Windows

Take a look at the Group Policy settings for Windows Update in gpedit.msc, in particular No auto-restart with logged on users for scheduled automatic updates installations:

They are in:

Local Computer Policy
|-Computer Configuration
  |-Administrative Templates
    |-Windows Components
      |-Windows Update

Change "No auto-restart with logged on users.." to enabled. GPO No Auto-Restart

Essentials segment Windows users

acatalept contributes the following solution for users of products offering the essential NT experience.

For non-Professional versions of Windows that don't have Group Policy Editor (gpedit.msc), you can accomplish the same thing as above in the Registry Editor. Navigate to this node (you may need to run it as Administrator):

HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\WindowsUpdate\AU

There, create a new DWORD (32-bit) value named NoAutoRebootWithLoggedOnUsers and set the value to 1. Then reboot for the change to take effect. See Pete's Stop Windows 8 Rebooting Due To Updates for steps.

Louis

Posted 2012-10-22T09:15:51.600

Reputation: 18 859

1I did the GPEDIT trick, the regedit trick, everything I could find -- it still restarted on me -- I was logged into the box and actively using it, I had long running operations going -- that were hours in -- it still restarted. What a bunch of crap. – BrainSlugs83 – 2014-09-03T06:34:18.640

Thank you, hopefully this will stop Microsoft's Intune from restarting my computer after 2 minute countdown (yes, only 2 minutes!) in the middle of the work while I have numerous documents opened, vmware player running etc. This is the most awful and destructive OS feature I encountered in my professional career as a software developer. – Ivan G – 2014-11-24T15:26:09.103

19This should be the accepted answer. The current accepted answer is completely false. After 2 prompts, which I closed, Win8 rebooted while I was still typing. When it came back up, I made sure to enable this GP setting. – Kasey Speakman – 2013-01-12T09:30:45.577

4Based on the experience I just had about 10 minutes ago, this needs to be enabled before you get the 5 minute warning...probably before you get the 15 minute warning too. – James Johnson – 2013-02-16T09:28:55.540

1I did that last time my computer wanted to restart on me, and thought I was fine, but a few minutes ago, I just got the 15 minute warning again – Sam I am says Reinstate Monica – 2013-03-22T15:17:05.067

@SamIam, I think you have to restart your computer for the changes to take effect. It works for me. – Sam – 2013-03-28T08:41:15.090

1@Sam I made the change the previous time that it wanted to restart. my computer has restarted many times since then – Sam I am says Reinstate Monica – 2013-03-28T14:08:51.830

@SamIam please notice Note: This policy applies only when Automatic Updates is configured to perform scheduled installations of updates. If the "Configure Automatic Updates" policy is disabled, this policy has no effect. Which means if you don't also set the Configure automatic updates policy to enabled, this doesn't work. – Destrictor – 2013-04-13T22:55:50.300

@jontro See James Johnson's comment. If you are getting prompted, then it is past the point where the Group Policy would stop it. The GP should stop it from prompting you at all next time. – Kasey Speakman – 2013-04-16T19:59:20.310

1Also, "I would be surprised if Windows would really restart while you're using it": it really does. You can have 14 different applications open, all with unsaved data, and it will still restart. I'm telling you, HAL had nothing on Windows 8. – Martha – 2013-04-26T15:34:52.677

@Martha @Louis For non-Professional versions of Windows that don't have Group Policy Editor (gpedit.msc), you can accomplish the same thing in the Registry Editor (regedit.exe) (you may need to run it as Administrator): under HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\WindowsUpdate\AU create a new DWORD (32-bit) value named NoAutoRebootWithLoggedOnUsers and set the value to 1. Then reboot for the change to take effect. See http://www.petenetlive.com/KB/Article/0000773.htm

– acatalept – 2013-05-16T13:51:13.797

If you want to avoid this prompt then choose to install Windows Update manually. Windows 8 provides 2 days before it will force you to restart. This was one of the major changes from Windows 7 which will basically right away or nag you until you do. – Ramhound – 2014-04-12T17:34:00.670

5The 'except' part is only true if W8 can actually detect that accurately. It can't - eg unsaved form content on web pages, custom apps, etc. Several times I've lost work due to this. – None – 2013-01-14T13:53:13.893

6thank you whoever chose this to be as a feature in Windows 8. I could no believe my eyes as it actually did reboot while I was working and I saw all my work disappear before my eyes. Somethings cannot be just saved. – ericosg – 2013-06-17T04:12:24.850

Vista too will reboot while you're using it, at least under some circumstances. I'd recommend always setting the updater to require your acceptance to begin the update install. On Vista that's Windows Updates -> Change Settings -> "Download updates but let me choose whether to install them" – Daniel R Hicks – 2013-09-18T20:26:54.430

if you are afraid of losing all your tabs in Chrome, there is a setting where all of your tabs in the last Chrome window open are saved, so that you can resume them when the computer is restarted or you open Chrome again. settings -> on Startup (section) – Malachi – 2014-04-22T17:51:13.717