Code 43: Windows Has Stopped This Device

What causes Code 43

• One of the drivers controlling the device told Windows that the device failed, when Windows asked for the device's state (Microsoft Learn).
• For drivers built on the Windows Driver Framework, Microsoft notes that the failure may be reported indirectly: the driver marks the device as failed or returns an error from one of its routines.
• Microsoft Support adds that if the basic steps have not helped, the hardware documentation or the manufacturer is the next place to look, which is the case where the device itself is at fault.

How to fix Code 43, safest step first

The steps follow Microsoft's recommended resolution for this code, in its order, with a reversible step first. Each one says how to put back what it changed.

1. 01

   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.

2. 02

   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.

3. 03

   Uninstall the device and reinstall it (Microsoft's recommended fix)

   In Device Manager, right-click the device and choose Uninstall device, confirm, then choose Action > Scan for hardware changes (or restart). Windows detects the device again and installs a driver for it. Keep the manufacturer's driver package to hand first: Windows may ask for it if it has no driver of its own.

   To undo: If Windows puts back a driver you did not want, use Roll Back Driver when it is offered, or install the driver you kept. The restore point from the first step brings back the whole driver configuration.

4. 04

   Ask the manufacturer when the code comes back

   If Code 43 returns with a clean reinstall, Microsoft's advice is to check the hardware documentation or contact the manufacturer for help diagnosing the device. For a plug-in device, trying another port or cable tells you whether the problem moves with the device.

   To undo: Nothing to undo: this step only gathers information.

Check it yourself

1. 01

   List every device with this code (Command Prompt or PowerShell)

   Available from Windows 10, version 1903. Each device is listed with its instance ID and the problem code with its name, CM_PROB_FAILED_POST_START. No administrator rights needed; nothing is changed.

   pnputil /enum-devices /problem 43

   cmdCopy
2. 02

   Or with PowerShell

   Device Manager shows the same code on the General tab of the device's Properties, in the Device status box.

   Get-PnpDevice | Where-Object { [int]$_.ConfigManagerErrorCode -eq 43 } |
     Format-Table Status, Class, FriendlyName, Problem

   PowerShellCopy