Log Dejargonizer

Windows System Log · Event 129

Event 129: A storage controller reset the drive

A drive stopped responding for long enough that the storage driver reset it. The machine usually freezes briefly when this happens. It points at the drive, the cable, or the controller — and on solid-state drives, often at outdated firmware.

Also written as 129Event ID 129storahci 129Reset to device was issuediaStorA 129

What it means for you

On a personal computer

Your drive stopped responding and Windows had to restart it, which is usually what a short freeze feels like. Check for a firmware update for the drive first — this is a common and fixable cause on solid-state drives.

For an analyst

Note the provider — storahci, iaStorA, and vendor-specific drivers each produce this. On virtual machines it usually reflects host storage latency rather than a guest problem. Frequent resets often precede a DPC watchdog crash.

What it looks like

Sanitised. Addresses come from the RFC 5737 documentation ranges.

Sample
Reset to device, \Device\RaidPort0, was issued.

The fields that decide it

Everything else in the log line is context.

Provider name
Which storage driver issued the reset. storahci is the Microsoft AHCI driver; iaStorA and similar are vendor drivers.
Device
Which port or device was reset, written as \Device\RaidPort0 or similar.
Frequency
Isolated resets happen. Repeated ones under load indicate a real fault.

Ordinary reasons this happens

Most of the time it is one of these.

  • A one-off timeout under unusual load.
  • Aggressive drive power management putting a disk to sleep and then timing out waking it.
  • Host storage latency in a virtual machine, reported by the guest as a device timeout.
  • A drive with outdated firmware that occasionally stalls — common enough to be the first thing to check.

What to do next

  1. Check for a firmware update for the drive. On solid-state drives this resolves a substantial share of these.
  2. Update or change the storage driver — switching between vendor and Microsoft AHCI drivers resolves some cases.
  3. Check the cable and port on desktop machines.
  4. Disable aggressive link power management if resets happen when the machine is idle.
  5. On a virtual machine, look at host storage latency rather than the guest.
  6. Check for Events 7 and 51, and read SMART data, to see whether the drive is failing rather than stalling.

Queries to run

powershell The provider name identifies which storage driver is involved, which determines what you update. 
Get-WinEvent -FilterHashtable @{LogName='System'; Id=129} -MaxEvents 50 | Select-Object TimeCreated, ProviderName, Message | Format-List
powershell Firmware versions for every drive. Compare against the manufacturer's current release before anything else. 
Get-PhysicalDisk | Select-Object FriendlyName, MediaType, FirmwareVersion, HealthStatus

Common questions

What causes Event 129 storahci resets?

A drive that did not respond to a command in time, so the driver reset it. The usual causes are outdated solid-state drive firmware, a failing or loose cable, aggressive drive power management, or — on virtual machines — storage latency at the host. Check firmware first; it resolves a large share of these.

Does Event 129 mean my SSD is dying?

Not usually. On solid-state drives it more often reflects a firmware bug or a power management setting than physical failure. Check the SMART wear indicator and the reallocated sector count: if those look healthy, update the firmware and the storage driver before considering replacement.

Why does my computer freeze for a few seconds and then log Event 129?

Because the freeze is the reset. When a drive stops responding, everything waiting on it stalls until the driver resets the device and input and output resumes. The freeze and the event are the same incident.

Read next

Mentioned by

Vendor documentation

Last reviewed 28 August 2026