Code 38: A Previous Instance of the Driver Is Still in Memory

What causes Code 38

• An earlier instance of the driver is still loaded, because of a wrong reference count or a race between loading and unloading.
• The driver is named by more than one AddService directive in one or more of its INF files.

How to fix Code 38, 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

   Restart the PC (Microsoft's recommended fix)

   Use Start > Power > Restart rather than Shut down, so Windows starts the device from scratch.

   To undo: Nothing to undo: a restart changes no setting.

2. 02

   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.

3. 03

   If it returns after every restart, reinstall the driver

   A Code 38 that keeps coming back points at the driver package itself, for example one whose INF files register the same service more than once. Uninstall the device, scan for hardware changes, and install the manufacturer's current driver if Windows does not bring back a working one.

   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.

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_DRIVER_FAILED_PRIOR_UNLOAD. No administrator rights needed; nothing is changed.

   pnputil /enum-devices /problem 38

   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 38 } |
     Format-Table Status, Class, FriendlyName, Problem

   PowerShellCopy