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DEVICE MANAGER ERROR · CM_PROB_UNSIGNED_DRIVER

Code 52: Windows Cannot Verify the Digital Signature

The driver for the device is not signed the way 64-bit Windows requires, or the signature does not check out, so Windows refused to start it. The message is a warning as well: a file with a bad signature can be damaged, or not what it claims to be.

WHAT WINDOWS SHOWS

Windows cannot verify the digital signature for the drivers required for this device. A recent hardware or software change might have installed a file that is signed incorrectly or damaged, or that might be malicious software from an unknown source. (Code 52)

Wording from Microsoft's documentation for CM_PROB_UNSIGNED_DRIVER. Device Manager shows it on the General tab of the device's Properties.

TECHNICAL SUMMARY

Code52
Windows nameCM_PROB_UNSIGNED_DRIVER
Where you see itDevice Manager > the device's Properties > General > Device status
In Tweaky DriverNeeds attention

What causes Code 52

  • The device did not start on 64-bit Windows because its driver is not digitally signed (Microsoft Learn).
  • The driver does not comply with the kernel-mode code signing policy; Microsoft Support adds that the driver may be corrupted.

How to fix Code 52, 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. 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. 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. Get a driver from the hardware manufacturer

    Download the current driver for your exact model from the manufacturer's support page and install it. Microsoft is explicit that for end users the only way to avoid this error is to install a digitally signed driver for the device.

    To undo: Roll Back Driver on the Driver tab returns to the driver you had, or apply the restore point.

Check it yourself

  1. 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_UNSIGNED_DRIVER. No administrator rights needed; nothing is changed.

    pnputil /enum-devices /problem 52
    cmd

  2. 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 52 } |
  Format-Table Status, Class, FriendlyName, Problem
    PowerShell

What Tweaky Driver does with Code 52

Needs attention

Tweaky Driver lists a Code 52 device under Diagnostics > Devices as Needs attention, with its code. It offers no driver for a device in this state and never changes Windows' driver signing settings. Its repair offers through Windows Update are limited to Codes 10 and 43.

Tweaky Driver, the driver checker that shows its sources — free for Windows 10 and 11.

Common questions

Should I turn off driver signature enforcement to fix Code 52?

No. Microsoft's guidance for end users is that the only way to avoid this error is to obtain and install a digitally signed driver. Loading unsigned drivers is described only as a development and test method for driver writers.

Is a Code 52 device infected?

Not necessarily. The message lists three possibilities: a file that is signed incorrectly, a damaged file, or software from an unknown source. Getting a signed driver from the manufacturer covers all three.

Why did Code 52 appear after an update?

Windows checks driver signatures every time it loads them. If a recent change installed a driver whose signature Windows does not accept, roll back to the previous driver while you look for a signed version.