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Event ID 12: The operating system started at system time

Windows Event ID Lookup: What Windows event IDs mean: 4625, 4624, 4740, 6008, 41, 7045, 1102 and 3,000 more, with Windows' own message text, the fields and what to check.

Look up a Windows event ID from Event Viewer, a SIEM alert or a log export: what it means, the fields it records, and what to check. Many IDs are used by more than one source (event 41 is both a Kernel-Power crash and a boot error), so every definition is shown, the one people usually mean first. The message text is Windows' own, read from the event providers of Windows 10.0.26200.0, 2026-10-28; the notes are ours, based on Microsoft's security auditing reference.

Try: 4625, 4624, 4740, 6008, 41, 1074, 7045, 1102, 4104, 1149

The operating system started at system time

Event 12
Kernel-General
System log
Information
Message and fields (as Event Viewer shows them) 
The operating system started at system time ….

Variable … requires … bytes and was set with status

Event 12
Kernel-Boot
System log
Information
Message and fields (as Event Viewer shows them) 
Variable … requires … bytes and was set with status ….

Time Provider NtpClient: This machine is configured to use the domain hierarchy to determine its time source, but it is the AD PDC emulator for the domain at the root of the forest, so there is no machine above it in the domain hierarchy to use as a time source.

Event 12
Time-Service
System log
Warning
Message and fields (as Event Viewer shows them) 
Time Provider NtpClient: This machine is configured to use the domain hierarchy to determine its time source, but it is the AD PDC emulator for the domain at the root of the forest, so there is no machine above it in the domain hierarchy to use as a time source. It is recommended that you either configure a reliable time service in the root domain, or manually configure the AD PDC to synchronize with an external time source. Otherwise, this machine will function as the authoritative time source in the domain hierarchy. If an external time source is not configured or used for this computer, you may choose to disable the NtpClient.

NTFS KSR data prepare failed.

Event 12
Ntfs
System log
Warning
Message and fields (as Event Viewer shows them) 
NTFS KSR data prepare failed.

           Volume GUID: …
           Device Name: …
           Error: …
           Failure Status: …           Source Tag: …

Bus change detect notification

Event 12
StorPort
System log
Information
Message and fields (as Event Viewer shows them) 
Bus change detect notification

An error occurred while building a certificate context

Event 12
Security-Kerberos
System log
Information
Message and fields (as Event Viewer shows them) 
An error occurred while building a certificate context: …

ProviderInfo for GroupOperationId = …; Operation = …; HostID = …; ProviderName = …; ProviderGuid = …; Path

Event 12
WMI-Activity
WMI-Activity/Operational log
Information
Message and fields (as Event Viewer shows them) 
ProviderInfo for GroupOperationId = …; Operation = …; HostID = …; ProviderName = …; ProviderGuid = …; Path = …

SMB2 Request Write

Event 12
SMBServer
SMBServer/Operational log
Information
Message and fields (as Event Viewer shows them) 
SMB2 Request Write

BITS stopped listening for peer-client requests.

Event 12
Bits-Client
Bits-Client/Operational log
Information
Message and fields (as Event Viewer shows them) 
BITS stopped listening for peer-client requests.