Code 12: This Device Cannot Find Enough Free Resources

What causes Code 12

• Two devices were assigned the same I/O ports, the same interrupt or the same DMA channel, by the BIOS, by Windows, or by both.
• The BIOS did not allocate enough resources to the device; Microsoft's example is a USB controller left without an interrupt because of an invalid multiprocessor (MPS) table.

How to fix Code 12, 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

   Find the conflict in Device Manager (Microsoft's recommended fix)

   Open the device's Properties > Resources tab: the Conflicting device list names the other device. View > Resources by type shows every assignment. Disabling the device you need less, as the message suggests, frees the resource.

   To undo: Re-enable the other device with Enable device.

3. 03

   Check the firmware settings

   Because the BIOS can also cause this code, a firmware update or default BIOS settings from the PC or motherboard maker can be the real fix. Note every setting before changing it.

   To undo: Set the BIOS options back to the values you noted, or load the previous firmware if the maker allows it.

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_NORMAL_CONFLICT. No administrator rights needed; nothing is changed.

   pnputil /enum-devices /problem 12

   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 12 } |
     Format-Table Status, Class, FriendlyName, Problem

   PowerShellCopy