Show Non-Present Devices in Device Manager and Clean Them Up

**Get-PnpDevice** lists present and non-present devices separately. The count of non-present entries shows whether a cleanup is worth the risk.

Get-PnpDevice | Group-Object Present | Select-Object Name,Count
Get-PnpDevice -PresentOnly | Measure-Object
(Get-PnpDevice | Where-Object { -not $_.Present }).Count

The variable is read by the Device Manager process at start. Set it in the machine environment so the setting survives a new shell.

[Environment]::SetEnvironmentVariable('devmgr_show_nonpresent_devices','1','Machine')
$env:devmgr_show_nonpresent_devices = '1'
devmgmt.msc
# View > Show hidden devices

A ghost with a problem code or one that holds a COM port is worth removing. A device you may plug in again is not: Windows will reinstall it, but the profile is lost.

Get-PnpDevice | Where-Object { -not $_.Present } | Select-Object Class,FriendlyName,InstanceId | Sort-Object Class
Get-PnpDevice -Class Ports | Where-Object { -not $_.Present } | Select-Object FriendlyName,InstanceId,Status

**pnputil /remove-device** removes a specific instance by its InstanceId. That is precise and does not touch present hardware.

$id = (Get-PnpDevice | Where-Object { -not $_.Present -and $_.FriendlyName -like '*USB Serial*' } | Select-Object -First 1).InstanceId
$id
pnputil /remove-device "$id"
Get-PnpDevice | Where-Object InstanceId -eq $id

Removing every non-present entry of one class fixes port and letter conflicts. Do it per class, never across the board, and never for storage controllers.

Get-PnpDevice -Class Ports | Where-Object { -not $_.Present } | ForEach-Object { pnputil /remove-device $_.InstanceId }
Get-PnpDevice -Class Ports | Select-Object FriendlyName,Present,Status

A scan for hardware changes restores anything that is actually connected. The remaining list should show only the hardware you own.

pnputil /scan-devices
Get-PnpDevice -PresentOnly | Group-Object Class | Select-Object Name,Count | Sort-Object Count -Descending
Get-PnpDevice | Where-Object { -not $_.Present } | Measure-Object