Update
Added Dialog_RebootDTU, Dialog_RebootForcedDTU, RebootWithUXForceOthers, and a few more items that I apparently missed. Thanks to @0gtweet who spotted some of the missing items, and rebooted his box on the way 🙂
Old Post
Have you ever got annoyed by this popup?

I got curious where they come from and after running sysmon I quickly discovered they come from the invocation of MusNotification.exe and MusNotificationUx.exe.
This one in particular is a lunch of:
MusNotificationUx.exe Dialog_EngagedFourthReminder 0
The Dialog_xxx is a very unique keyword, so after quick search I discovered the whole gamut of similar messages hidden inside the UserProcess:: GetNotificationCommandLineArguments routine inside the MusNotification.exe:
- Dialog_AllowSchedulingFirstReminder
- Dialog_AllowSchedulingForcedReminder
- Dialog_AllowSchedulingPerAUPolicy
- Dialog_AllowSchedulingRebootFailed
- Dialog_AllowSchedulingSecondReminder
- Dialog_AllowSchedulingThirdReminder
- Dialog_AllowSchedulingWarning
- Dialog_CantDownloadUpdate
- Dialog_CantInstallUpdate
- Dialog_DataMigrationFailed
- Dialog_DownloadAvailable
- Dialog_DownloadNeedUserAgreementPerCTA
- Dialog_EngagedFourthReminder
- Dialog_EnhancedEngagedAcceptAuto
- Dialog_EnhancedEngagedForcedPrecursor
- Dialog_EnhancedEngagedForcedWarning
- Dialog_EnhancedEngagedRebootFailed
- Dialog_EnhancedEngagedRebootImminent
- Dialog_EnhancedEngagedRebootReminder
- Dialog_EnhancedEngagedSecondRebootReminder
- Dialog_ExpeditedReboot
- Dialog_InstallNeedEula
- Dialog_InstallNeedUserAgreement
- Dialog_LowUptime
- Dialog_PolicyDeadlineApproaching
- Dialog_PolicyDeadlineEngagement
- Dialog_PolicyDeadlineRebootFailed
- Dialog_PolicyDeadlineRebootImminent
- Dialog_PolicyDeadlineUserScheduled
- Dialog_RebootActiveHoursForcedReminder
- Dialog_RebootActiveHoursForcedWarning
- Dialog_RebootActiveHoursImminent
- Dialog_RebootActiveHoursUserSelected
- Dialog_RebootDTU
- Dialog_RebootForcedDTU
- Dialog_RebootImminent
- Dialog_RebootPolicyEnabledForcedWarning
- Dialog_RebootPostponeMgmt
- Dialog_RebootWarning
- Dialog_ScheduleUpdate
- Dialog_ScheduleUpdateFailed
- Dialog_SuggestedActiveHours
You can pick up any of them and run via a similar invocation using MusNotificationUx.exe e.g.
MusNotificationUx.exe Dialog_CantDownloadUpdate 0

and others:


Apart from being a gimmick these invocations could be a good social engineering add-on to malware repertoire, and would certainly add a lot of credibility to rogue antispyware software back in a day.
There also seem to be a possibility of a Lolbin as the invocations of MusNotificationUx.exe via MusNotification.exe refer to %SYSTEMROOT% environment variable as opposed to path retrievwed using GetSystemDirectory — still a questionable programmer’s choice prevalent in many native OS binaries.
Finally, there is also a whole list of Toast_* invocations, which I have not figured out yet how to execute properly:
- Toast_CompatIssue
- Toast_DesktopKeepOnReminder
- Toast_DownloadNeedMoreSpace
- Toast_DownloadNeedUserAgreement
- Toast_DownloadNeedUserAgreementPerCTA
- Toast_DownloadNeedWifi
- Toast_DownloadViaCellularNeedUserAgreement
- Toast_EngagedFirstReminder
- Toast_EngagedRebootFailed
- Toast_EngagedRebootWarning
- Toast_EngagedSecondReminder
- Toast_EngagedThirdReminder
- Toast_EnhancedEngagedRebootReminder
- Toast_FailedDiskSpaceCheck
- Toast_FairWarningDesktop
- Toast_FairWarningLaptop
- Toast_FairWarningPolicyNotifyDeadline
- Toast_InstallBlocked
- Toast_InstallNeedEula
- Toast_InstallNeedMoreSpace
- Toast_InstallNeedUserAgreementPerAUPolicy
- Toast_KeepAliveOnBatteryWarning
- Toast_LaptopPlugInReminder
- Toast_LowUptime
- Toast_MeteredConnection
- Toast_NotifyToDownload
- Toast_NotifyToInstall
- Toast_OOBEDownloadInProgress
- Toast_PersistentReadyToReboot
- Toast_PolicyDeadlineEngagement
- Toast_RebootActiveHoursForcedReminder
- Toast_RebootActiveHoursImminent
- Toast_RebootNeedUserAgreementPerAUPolicy
- Toast_RebootOtherUsers
- Toast_RebootReminder
- Toast_SuggestedActiveHours
- Toast_UpdateFailed
Last, but not least, there are some additional options the tool accepts, in particular:
- RebootWithUXForceOthers
- RebootWithUX
- ClearActiveNotifications
- QueryNotificationState
- -Embedding
- /CV – correlation vector
- /MusUxStateString
- /ToastAction, where the action can be one of these:
- AlwaysAllowAutoUpdates
- DeferRestartInHour
- DeferRestartNow
- ForcedRemRestartNow
- ImmAnotherTime
- ImmRestartNow
- NotifyRestartNow
- OthersPickTime
- OthersRestartAnyway
- RemPickTime
- RemRestartNow
- RemSnooze
- RestartFailedRetry
- RestartTonight
- RestartWarningOption
- Settings
- Setup
- SnoozeUx
- SuggestedAHConfirm
- SuggestedAHDontChange
- WarnPickTime
- WarnRestartNow
- dismiss
- eDTERestartTonight
- /ToastLaunchTimestamp