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Event ID 84: ACPI thermal zone … has … active cooling

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

ACPI thermal zone … has … active cooling.

Event 84
Kernel-Power
System log
Information
Message and fields (as Event Viewer shows them)
ACPI thermal zone … has … active cooling.             
EventTime = …             
_AC0 = …K             
_AC1 = …K             
_AC2 = …K             
_AC3 = …K             
_AC4 = …K             
_AC5 = …K             
_AC6 = …K             
_AC7 = …K             
_AC8 = …K             
_AC9 = …K             
_TMP = …K

Seal and Store on Disk Status

Event 84
Kernel-Boot
System log
Information
Message and fields (as Event Viewer shows them)
Seal and Store on Disk Status

Status: …
OsDeviceId: …
SystemRoot: …
PcrSealMask: …
LatchTheUnlatched: …
UpgradedAntirollbackPolicyExists: …
EncryptionStatus: …
KeyPkgIdTpmCounterValue: …
EncryptedLKeyArrayPkgSize: …
EncryptedLKeyPkgPdGuid: …
UnlatchedUnsealPolicySize: …
UnlatchedProtectorExists: …
LatchedUnsealPolicySize: …
LatchedProtectorExists: …

Latched unseal policy

Version: …
VarDataOffset: …
StructureSize: …
PolicyVersion: …
PolicyHashLength: …
WinloadSVN: …
WinresumeSVN: …
BootmgrSVN: …
LKeyPkgId: …

Unlatched unseal policy

Version: …
VarDataOffset: …
StructureSize: …
PolicyVersion: …
PolicyHashLength: …
WinloadSVN: …
WinresumeSVN: …
BootmgrSVN: …
LKeyPkgId: …