Connected User Experiences and Telemetry
The `Start` DWORD defines the startup type of the Windows service named `DiagTrack`.
since 0.9.8.11
Purpose
Show registry keys (1)
HKLM\SYSTEM\CurrentControlSet\Services\DiagTrack\Start
The Start DWORD defines the startup type of the Windows service named DiagTrack. A value of 4 represents SERVICE_DISABLED: the service cannot be started, and attempts to start it fail with ERROR_SERVICE_DISABLED.
Depending on the device's diagnostic data settings, DiagTrack manages the event-driven collection and transmission of Windows diagnostic data and diagnostic logs. These component functions are unavailable while the service is disabled.
Notes
Additional effects
The service also enables certain features that support in-application and connected user experiences. Microsoft does not publish an exhaustive list of those features, so the exact functional impact can vary by Windows version and by the applications in use.
Security
Disabling the service reduces the diagnostic data processed and transmitted through DiagTrack. It does not disable every source of diagnostic or telemetry data. Crash reports and memory dumps, for example, are handled separately by Windows Error Reporting. On certain Windows versions and in certain regions, Microsoft Edge diagnostic data is also collected separately from Windows diagnostic data.
This registry value does not block network endpoints. Other Windows components and applications can continue to transmit their own diagnostic or usage data.
Possible side effects
Microsoft Intune Endpoint analytics requires the DiagTrack service to be enabled and running. Disabling it can therefore prevent a device from supplying the required functional data and from being evaluated correctly in Endpoint analytics.
Microsoft Defender for Endpoint reporting can also be affected in some circumstances. However, beginning with Windows 10 build 1809, the EDR service no longer has a direct dependency on DiagTrack; Microsoft states that EDR cyber evidence can still be uploaded when DiagTrack is not running.
Notes
This registry value controls the startup type of one Windows service. It is distinct from the Group Policy and MDM settings that select the amount of Windows diagnostic data.
Changing the startup type does not immediately terminate an already running service. For a running service, the changed configuration takes effect after the service has stopped.
Microsoft documentation
Microsoft Learn: ChangeServiceConfigW function — service start types
Microsoft Learn: Configure Windows diagnostic data in your organization
Microsoft Learn: Endpoint analytics overview
Microsoft Learn: Troubleshoot Microsoft Defender for Endpoint onboarding issues