STOP CODE · 0x9F
DRIVER_
A driver was asked to change power state, for example to let its device sleep or wake, and did not complete the request. It shows up when the PC goes to sleep, wakes, hibernates or shuts down.
WHAT MICROSOFT SAYS
Microsoft's reference says this bug check "indicates that the driver is in an inconsistent or invalid power state". The common causes it lists include a power state transition that timed out and a device object blocking a power request. It notes that some driver issues are tied to hibernation and to suspending and resuming power.
From Microsoft's documentation, linked under Sources. Microsoft wrote its page for this code for programmers; the steps below are the ones it gives everyone else.
TECHNICAL SUMMARY
| Stop code | DRIVER_POWER_STATE_FAILURE |
|---|---|
| Value | 0x0000009F (0x9F) |
| Where you see it | At the bottom of the stop screen, and in the System event log after the restart |
| In Tweaky Driver | Stop codes are not read; driver versions are checked |
What causes DRIVER_
- A power state transition timed out: a driver took too long to put its device to sleep or wake it.
- A driver is holding on to a power request that Windows is waiting for.
- A driver freed its device while a power request was still outstanding.
- Microsoft also points at system firmware: it suggests checking whether an updated ACPI/BIOS or other firmware is available.
How to fix DRIVER_
The steps come from Microsoft's guidance, with the reversible ones first. Each one says how to put back what it changed. If Windows cannot start normally, Microsoft's basic steps say to start in safe mode and continue from there.
Write down the stop code and the file the screen names
Microsoft Support says the stop code appears at the bottom of the screen and, when Windows knows it, so does the name of the module that was running. If the screen went by too fast, the command under Check it yourself lists the stop codes Windows recorded, and Event Viewer > Windows Logs > System shows the errors logged around the restart.
To undo: Nothing to undo: this only reads information.
Before you change anything: note the driver and make a restore point
Open the device's Properties > Driver tab and write down the driver provider, date and version. Then select Start, type Create a restore point, open it, and on the System Protection tab choose Create. Microsoft notes that System Protection is not turned on by default; if Create is greyed out, choose Configure and turn it on for the system drive first.
To undo: A restore point changes nothing by itself. To go back later, run System Restore and pick it: Microsoft says it reverts system files, the registry and installed programs, and leaves your personal files alone.
Look for a warning icon in Device Manager
Right-click Start and open Device Manager. Microsoft's steps: see whether any device is marked with an exclamation point, right-click it and choose Update driver; if updating does not help, try disabling or uninstalling the device. The code shown in the device's Properties has its own page in our Device Manager section.
To undo: Roll Back Driver returns to the previous driver, a disabled device is enabled again from the same right-click menu, and an uninstalled one comes back with Action > Scan for hardware changes.
Update the driver the screen names
Microsoft's advice when a driver is identified in the bug check message is to disable the driver or check with the manufacturer for driver updates. In Device Manager, right-click the device and choose Update driver, or install the current package from the manufacturer's support page for your exact model.
To undo: Open the device's Properties > Driver tab and choose Roll Back Driver, or apply the restore point.
If it started after a driver update, roll the driver back
In Device Manager, right-click the device, choose Properties, open the Driver tab and select Roll Back Driver, then give a reason and confirm. Microsoft notes that you need administrator rights, and that going back to the previous driver often fixes a problem that appeared after an update. The button is greyed out when Windows kept no earlier driver for the device.
To undo: Rolling back is the undo for the update. To return to the newer driver, install it again with Update driver or from the manufacturer's package.
Test with power saving turned off
Microsoft suggests temporarily disabling power saving in Control Panel > Power Options to isolate the cause, because some driver problems only appear around sleep and hibernation. Note your current sleep settings, set sleep and hibernate to Never, and see whether the crashes stop.
To undo: Set the sleep and hibernate times back to the values you noted.
Take out what you added just before it started
Microsoft's first basic step for a stop code that keeps coming back is to remove new hardware: shut the PC down, disconnect the device and start again. Its bug check pages say the same about drivers and system services added recently: remove or update them, and work out what changed just before the first crash.
To undo: Reconnect the hardware, or install the program or driver again.
Check for a BIOS or firmware update
Microsoft's list ends with firmware: look on the PC or motherboard maker's support page for an updated system ACPI/BIOS or other firmware, and run the maker's hardware diagnostics.
To undo: A firmware update is not undone by a restore point. Install one only from the maker's page for your exact model and follow its instructions.
Check it yourself
List the stop codes Windows recorded (PowerShell)
Each entry gives the date, the stop code as a hexadecimal number with its four parameters, and where the dump file was saved. On the test PC, Windows 11 build 26300, this ran without administrator rights. An error saying no events were found means Windows recorded none. This stop code appears there as 0x0000009f.
PowerShellGet-WinEvent -FilterHashtable @{ LogName='System'; Id=1001; ProviderName='Microsoft-Windows-WER-SystemErrorReporting' } -MaxEvents 5 | Format-List TimeCreated, MessageList the driver packages installed on the PC
Shows every third-party driver package with its provider, class, version and date, so you can see what was installed around the first crash. Nothing is changed.
cmdpnputil /enum-drivers
What Tweaky Driver can and cannot do here
Driver version checkTweaky Driver does not read crash dumps or stop codes, so it cannot tell you which driver caused this screen. It helps with the step that comes after Windows names a driver: its scan lists every device with the installed driver version and shows whether Windows Update, the Microsoft Update Catalog or a manufacturer package it supports has a newer one, with the source and version in front of you before anything is installed. It does not change sleep or power settings and does not update BIOS firmware. A newer driver is no promise that the blue screen stops: the same code can come from hardware or from Windows itself.
Tweaky Driver, the driver checker that shows its sources — free for Windows 10 and 11.
Common questions
What does DRIVER_POWER_STATE_FAILURE mean?
A driver ended up in an inconsistent or invalid power state. In practice a driver did not finish a request to sleep or wake its device in time.
Why does DRIVER_POWER_STATE_FAILURE happen on sleep or wake?
Because that is when Windows sends power requests to every driver. Microsoft notes that some driver issues are related to hibernation and to suspending and resuming power, and suggests turning power saving off temporarily as a test.
Which driver causes DRIVER_POWER_STATE_FAILURE?
Any driver can. If Windows identified one, its name is on the blue screen; otherwise Microsoft suggests Device Manager, looking for devices marked with an exclamation point, and the System log in Event Viewer around the time of the crash.
Is turning off sleep a fix?
It is a test, not a fix: if the crashes stop, a driver that mishandles sleep is the likely cause, and updating or rolling back that driver is the real repair.