All sorts of bad things happen when we disable the Task Scheduler service, is that bad?


A customer disabled the Task Scheduler service by applying group policy to set Task Scheduler's startup mode to Off. When they did that, they found that a lot of stuff stopped working. For example, the Start menu would hang for several minutes. Search stopped working. "Any idea what tasks could be causing the issue?"

The customer liaison added "Obviously this is a bad idea, but I couldn't find any official statement to that effect."

Aha, the customer is looking for documentation that explicitly states that a bad idea is a bad idea, presumably because they want to shift the blame for their bad idea to Microsoft.

We responded that a bad idea is a bad idea, even if it's not written down anywhere.

In the meantime, the customer liaison was able to find official documentation that confirmed that a bad idea is a bad idea!

Guidance on disabling system services on Windows Server 2016 with Desktop Experience lists a bunch of services and what Microsoft has to say about disabling that service.

Task Scheduler
Service description Enables a user to configure and schedule automated tasks on this computer. The service also hosts multiple Windows system-critical tasks. If this service is stopped or disabled, these tasks will not be run at their scheduled times. If this service is disabled, any services that explicitly depend on it will fail to start.
Service name Schedule
Installation Always installed
StartType Automatic
Recommendation No guidance

Each service on the system is categorized as follows:

  • Should Disable: A security-focused enterprise will most likely prefer to disable this service and forego its functionality (see additional details below).
  • OK to Disable: This service provides functionality that is useful to some but not all enterprises, and security-focused enterprises that don't use it can safely disable it.
  • Do Not Disable: Disabling this service will impact essential functionality or prevent specific roles or features from functioning correctly. Therefore it should not be disabled.
  • (No guidance): The impact of disabling these services has not been fully evaluated. Therefore, the default configuration of these services should not be changed.

(Emphasis mine.)

Comments (53)
  1. Antonio Rodríguez says:

    Maybe there was some kind of war inside the customer’s organization. I have seen too much cases of “Microsoft bloats Windows with all those unnecessary services and processes” and “I’m smarter than Microsoft because I can disable some services”. No, you aren’t. You are just assuming something isn’t necessary because you don’t understand its function, which only proves the opposite: that you aren’t as smart as you think. But I digress. Maybe this customer is trying to fight some too-smart guy in their organization, and needs documents to prove their points before a pointy-haired boss.

    1. Pierre B. says:

      Both your reply and Raymond post befuddle me.

      Wanting to know what each process running in your OS does, if and why it is requiredd is not some sin. This is the reverse of the kernel-colored glasses. We get computer with pre-installed OS with pre-installed software. From the end-user persoective, there is a lot of undesired software being pushed down our throat. Desiring not to have to blindly trust vendor is a virtue, not a fault.

      1. Antonio Rodríguez says:

        I’m afraid you don’t get the point. What I complain about is those pundits which don’t know and don’t want to know, but even then criticize Microsoft’s design decisions. If you want to be critic of something (movies, art, software engineering…), you should at least try to learn something about the author’s motivations. If not, you end being like “Why did the architect place all those columns in the basement? They make parking my car so difficult!”.

      2. George says:

        Disabling a critical process and curiosity aren’t the same thing, and I’m sorry but that’s not an opposite example of kernel-coloured glasses.

    2. cheong00 says:

      Or it’s internal hardening guideline requires disabling that service. (Government and large organizations have these)

      To lift the restriction (don’t disable an item that marked as “disable” there) because it causes problem, you need official documentation to back up your claim.

  2. Koro says:

    The problem with the Task Scheduler service is that it has become the “new Autorun”: you never know when it’s going to start a process behind your back.

    Case in point: when you install Chrome, not only does it install TWO services, but it also installs a bunch of scheduled tasks to make sure its auto-update runs. If you don’t know about them and only delete the services, it still manages to update using the scheduled tasks! Took me a while to figure out where those processes were coming from.

    1. Klimax says:

      Autoruns from Sysinternals Suite helps there.

    2. skal says:

      Autoruns (from Sysinternals Suite) is your friend.

    3. Karellen says:

      So, because Chrome (or some other bit of software) installs tasks you don’t like, rather than pointing the finger at Chrome and uninstalling it until it learns to behave itself better, you’re saying that disabling the system-wide scheduler so that no tasks from any application can run instead sounds like a reasonable course of action?

      That’s like finding pests in your home and rather than calling an exterminator, burning your whole house down or moving to a different city!

      1. snarf blam says:

        No, he didn’t say that at all. All he said was that certain usage of it was problematic. And I have to agree. I’ve had situations software kept running that was causing problems, and had to go digging through services and task scheduler and remove every trace of it. Miss one and they all come back from the dead. Fun.

    4. Russ says:

      If your support staff doesn’t have the ability to Google how to disable auto update for X Program, then you probably need new support staff.

      Disabling task scheduler to stop a program from running is like saying we’re going to stop viruses by removing Mice from the computers so people can’t click on things.

  3. xcomcmdr says:

    Rule #1 of Tech Support :
    – “My Windows won’t update / won’t start / dragons come out of the screen”
    – “Did you disable some services ?”
    – “Yes”
    – “Well, there’s your problem !”

    1. Pilchard123 says:

      > dragons come out of the screen

      The disabled services version of nasal demons?

    2. D-Coder says:

      > dragons come out of the screen

      I hate it when that happens.

  4. Joshua says:

    This is really bad.

    So, they shouldn’t have disabled task scheduler. However, I can’t come up with an excuse for whatever crawling horror prevents the start menu from opening for minutes with task scheduler not running. The default login shell on a server needs really high resiliency.

    1. Richard says:

      Presumably there’s a scheduled task to update all the adverts, and if it doesn’t run then the Start popup has to download them then.

      Please, Raymond, for the love of all that is holy, bury that misfeature, the manager who came up with it and the product manager who gave it the go-ahead in a deep hole under half a ton of quicklime.

    2. Nathaniel Price says:

      Resiliency against what, exactly? Against stupid users that change things that they don’t understand that turn out to be required for the normal operation of the machine?

      Every program has dependencies. If Windows in its default configuration is somehow less stable or more buggy with Task Scheduler than without, you *might* have a point, but I’ve never heard of that being the case.

      1. Joshua says:

        Against many kinds of nonsense. Task scheduler is the kind of thing that you might want in delay start. Maybe the networking stack is completely borked (seen that hang once, not too good when the user’s start menu is on a unc path). Maybe the cryptographic service is taking its sweet time coming up. Some settings panes don’t work as the built-in admin (safe mode). Maybe WMI is dead meat (seen it too often). Maybe RPCSS is a goner (seen it). Point being, the only remotely excusable one is the UNC start menu or desktop when the network is hosed and even that really should just load asynchronously.

    3. Azarien says:

      @Joshua: maybe (just maybe) the start menu depends on some results that were supposed to be generated by a scheduled task. Or perhaps the start menu tries to communicate with the task scheduler (e.g. to schedule a task) and decides to wait instead of failing immediately as a way to avoid some race condition (the taskbar is intialized during system startup, and during startup the system as a whole isn’t fully stable yet…)

      1. I don’t know for sure, but the second theory sounds likely.

        1. DWalker07 says:

          I am baffled why the Start menu would depend on anything coming from Task Scheduler. I don’t see tasks listed in the Start menu.

          I don’t know the internals, but both the first and second scenarios sound very weird. Why would clicking on the Start menu need to schedule a task?

          1. Joshua says:

            It’s Cortana.

  5. DWalker07 says:

    I wonder if using the Task Scheduler service to host multiple Windows system-critical tasks was a good idea. :-) The service could have been named “Task Scheduler and other important services”.

    However, the design of Windows is in Microsoft’s court, not ours.

  6. Cesar says:

    “If this service is disabled, any services that explicitly depend on it will fail to start.” So perhaps the culprit wasn’t Task Scheduler itself, but some other service that depends on it (perhaps to schedule tasks) that didn’t start. The Start menu hanging looks like a timeout waiting for that service.

    1. DWalker07 says:

      “If this service is disabled, any services that explicitly depend on it will fail to start.”

      That’s ALMOST a tautology; at least it should be obvious, and not need to be declared for each service.

      1. Kenn says:

        Much more useful would be to automatically add the text “If this service is disabled, the following services will not start: A, B, C, D, …”

        1. And how would you automatically generate that text?

          1. DWalker07 says:

            Each service will already show you the other services it depends on.

          2. Sure, but how does the Web page auto-update whenever the dependencies change?

  7. FS says:

    Now the question becomes: Why is it a bad idea? I know, “the service also hosts multiple Windows system-critical tasks”, but is hosting system-critical tasks in Task Scheduler not a bad idea in the first place; wouldn’t it be better if they were hosted or executed separately from the non-critical ones, for security and reliablity reasons? And what is the definition of “system-critical”? Does it mean it is required so badly that I’ll get a BSOD if it isn’t available, or does it also apply to stuff that is not really necessary for the system to operate correctly (like, for example, some kind of data collection or update task) and is only considered critical because it fulfills a certain purpose?

    1. The tasks themselves are hosted in a separate process (taskhostw.exe). Looking at the tasks on my system, I see some that people might interpret as system-critical, like those which maintain security policy and which keep the system up to date.

    2. Russ says:

      Have you ever looked at the hundreds of things that are in task scheduler?

      One look at those should tell anybody that it’s a bad idea to disable that for any reason.

      1. Ben Voigt says:

        One superficial (but not quick, because there are so many) of those, which I have conducted quite a few times on different Windows versions, taught me that nearly all of the hundreds of things should have been disabled by default and only enabled after the user opts in, preferably explicitly, but at the very least by running the niche applet that the task feeds data to. If the user doesn’t ever run that applet (and there is a lot of bloat bundled with Windows, although perhaps less in-your-face than the days when a “clean” install left a desktop filled with paid advertisements for various ISPs) then the tasks needn’t ever run either.

  8. Aha, the customer is looking for documentation that explicitly states that a bad idea is a bad idea, presumably because they want to shift the blame for their bad idea to Microsoft.

    That’s not necessarily a blame-pusher or Microsoft-hater. This person could be a hard-working, harassed and frustrated Wikipedian!In Wikipedia, the principle of verifiability rules supreme. But also in Wikipedia, where everyone is allowed to edit, not only credentials are not required, but also shunned. So, a sadists crackpot has the equal status as a distinguished genius computer scientist with eleven Microsoft certificates and 35 years of work experience. It is no surprise that you often find the former harassing the latter with a {{citation needed}} tag, especially when the latter tries to promote an article to the Featured level.

    1. warrens says:

      I see you’re still bitter about being banned from editing on Wikipedia.

      1. LOL. Out of experience, I’d say you made up your mind that I must be bitter long before even reading my comment. You’d be in serious trouble if someone hold you at gunpoint at say “define your parameters of bitterness!” 😉 That only happens in Hollywood flicks though.

        How’s thing going on between you and Codename Lisa, by the way? Does she still send you “Thanks” message and you bitterly revert them? (Hmm… Talk about bitterness… maybe you should look closer at hand.)

        1. warrens says:

          She got banned, too.

          1. Anonymous says:
            (The content was deleted per user request)
          2. I am afraid you are poorly informed.

            What you see is a uw-uhblock-double, not a ban. It means the username got vacated, someone tried to grab it and ride the good reputation of the old owner, but was stopped. The only time in Wikipedia that a username gets vacated like this is when a user is honorably discharged from service (WP:VANISH or some ArbCom discharge).

            And since the only person I cared about has left Wikipedia, I am officially not interested in it. Actually, I’ve been much more cheerier since I left.

    2. cheong00 says:

      Emmm… I heard there is a policy that, if an entry in Wikipedia is found to attract inappropiate edits, the article will be restricted and only allow edit performed by logged-in users with appropiate access level.

      See “Wikipedia:Protection policy” for detail.

      1. That’s true. But page protection often does exacerbate the matter instead of alleviating it. After all, it is impossible to tell if the {{citation needed}} insertion is a harmless citation request or systematic harassment, unless the admin attending to the matter is either an expert in the subject or having seen the long-term pattern of the involved editors. And one page cannot remain locked forever.

  9. David says:

    Obviously this is a bad idea, but I couldn’t find any official statement to that effect.

    I wouldn’t interpret this as wanting to shift blame to Microsoft.

    “This is obviously a bad idea, but I need to prove it to my boss, because he doesn’t believe me when I say it. He only believes official statements from Microsoft.”

  10. Andrey says:

    Even though still can’t understand how that might be that Start menu hang without any given error message for a few minutes. How comes that Start menu depends on Task Scheduler?

    Don’t get it wrong, but it’s seems to be stupid and is most cases counter intuitive for any user or even experienced system administrator. What’s next, once you disable Network Connections service, your Notepad will silently fail to load?

    1. Max says:

      A number of system tasks are run via the Task Scheduler, some of which are set to run on demand. For example, refreshing the parental controls settings and running maintenance tasks for the search index are both tasks that depend on the Task Scheduler, and both seem like the kinds of things the Start Menu might depend on.

      1. DWalker07 says:

        Why do parental controls settings need to be “refreshed”? Do they decay otherwise?

        1. If they were never refreshed, then you wouldn’t be able to change them!

        2. Max says:

          The parental controls might not be set up by the same user account and machine that they’re applied to. The computer has to check outside sources, such as the online Microsoft Accounts system. And for whatever reason, the task for checking the status of parental controls is run via custom conditions in Task Scheduler.

          There’s not necessarily any particular reason why it has to be that way. But there’s not necessarily any particular reason why it SHOULDN’T be that way. At some point, someone made an architectural decision that various Windows services and tasks would use the Task Scheduler (probably because it’s already set up to detect things like whether the system is busy and how long it’s been since a task was last run).

  11. Russ says:

    Jesus, some of you people would need a sign on the side of a volcano saying not to jump in for you to think it’s a bad idea.

  12. cheong00 says:

    Btw, if you present this guidance to “security experts”, I think a lot of them will not agree with it.

    Particularly, in a lot of hardening guidelines, the “Server” service is set to “Disabled” but this guidance listed it as “Do not disable”. And I wonder why “Microsoft iSCSI Initiator Service” is listed as “Do not disable” instead of “OK to disable” because there’s not much iSCSI device I seen in corporate/government environments, especially when there are also recommandation like “OK to disable if not a print server or a DC”.

  13. Max says:

    The question that goes unanswered is why they’re disabling it. Either it’s causing some sort of problem in their environment, or they’re forced to follow poorly-thought-out security guidelines. Usually, when someone wants documentation that a bad idea is a bad idea, it’s because their boss refuses to believe that it’s a bad idea.

  14. naficy says:

    I’m confused why we assume that the customer is wrong in seeking documentation?

    The mere existence of such guidance on “Disabling Windows Services” from microsoft, means that it is a valid act: The customer is right to want to disable “some” services. So they should seek documentation to do it correctly, shouldn’t they?

    Years ago, I’ve read topics on this very same blog that, for eg. you cannot rely on msvc runtime dlls to be always present in Windows directories, although we know that for some time, this was the case for a typical Windows installation. We were told that we should read the documentation and know that if something is not documented, it is not contractual, and may not last long. [1] The case of disabling a default-enabled Windows service is very much like that case for default-installed file.

    One should be shamed for not reading the documentation, not for seeking it.

    [1] Windows is not a Microsoft Visual C/C++ Run-Time delivery channel

  15. Mark kinsey says:

    Haha. Aha, “looking for documentation that explicitly states that a bad idea is a bad idea”

    Love It!

  16. paxdiablo says:

    I would think the phrase “The service also hosts multiple Windows system-critical tasks” would be reason enough to automatically upgrade the recommendation to “Do Not Disable” :-)

    Another possibility would be to allow MS to mark certain services as “Cannot Disable, Go Away, Leave Me Alone, You Goose!!”. Though, of course, that would almost certainly invoke a demand from certain people to allow them to do the same for non-MS services.

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