diff --git a/.github/workflows/cmake-windows.yml b/.github/workflows/cmake-windows.yml
index 4e9372ae..d052e0fe 100644
--- a/.github/workflows/cmake-windows.yml
+++ b/.github/workflows/cmake-windows.yml
@@ -168,29 +168,26 @@ jobs:
           New-Item -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\" -Name "AppPrivacy" -Force
           Set-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\AppPrivacy" -Name LetAppsAccessMicrophone -Value 0
 
-    - name: Start Windows Audio Service
+    - name: Wait for virtual audio endpoints
+      shell: pwsh
       run: |
-          Restart-Service -Name audiosrv -Force
-          $deadline = (Get-Date).AddSeconds(60)
-          do {
-              Start-Sleep -Seconds 2
-              $deviceNames = (Get-CimInstance win32_sounddevice).Name
-          } until (
-              ($deviceNames -match "VB-Audio Virtual Cable") -and
-              ($deviceNames -match "Virtual Audio Cable") -or
-              ((Get-Date) -gt $deadline)
-          )
+          # Restart the audio stack and poll until every endpoint FreeDV needs is
+          # actually enumerable, instead of starting a test and letting it abort
+          # with a fatal "device cannot be found" message box when a virtual
+          # cable endpoint hasn't come up (or has briefly dropped) yet.
+          & "${{github.workspace}}\ci\Wait-AudioDevices.ps1" `
+            -Playback  "${{ env.COMPUTER_TO_RADIO_DEVICE }}", "${{ env.COMPUTER_TO_SPEAKER_DEVICE }}" `
+            -Recording "${{ env.RADIO_TO_COMPUTER_DEVICE }}", "${{ env.MICROPHONE_TO_COMPUTER_DEVICE }}" `
+            -TimeoutSeconds 180
 
     - name: List audio devices
       shell: pwsh
       run: |
-          Get-CimInstance win32_sounddevice
+          Get-AudioDevice -List | Format-Table -AutoSize Index, Default, Type, Name
 
     - name: Set Windows default audio devices
       shell: pwsh
       run: |
-          Invoke-WebRequest https://github.com/frgnca/AudioDeviceCmdlets/releases/download/v3.1/AudioDeviceCmdlets.dll -OutFile AudioDeviceCmdlets.dll
-          Install-Module -Name AudioDeviceCmdlets -Force -Confirm:$false
           Get-AudioDevice -List | where { $_.Name -eq "${{ env.MICROPHONE_TO_COMPUTER_DEVICE }}" } | Set-AudioDevice
           Get-AudioDevice -List | where { $_.Name -eq "${{ env.COMPUTER_TO_SPEAKER_DEVICE }}" } | Set-AudioDevice
 
@@ -209,9 +206,13 @@ jobs:
     - name: Generate PGO data
       shell: pwsh
       working-directory: ${{github.workspace}}\FreeDV-Install-Location\bin
+      timeout-minutes: 25
       run: |
-          .\GeneratePGOProfiles.ps1 -RadioToComputerDevice "${{env.RADIO_TO_COMPUTER_DEVICE}}" -ComputerToRadioDevice "${{env.COMPUTER_TO_RADIO_DEVICE}}" -MicrophoneToComputerDevice "${{env.MICROPHONE_TO_COMPUTER_DEVICE}}" -ComputerToSpeakerDevice "${{env.COMPUTER_TO_SPEAKER_DEVICE}}" 
-      timeout-minutes: 10
+          & "${{github.workspace}}\ci\Invoke-PgoProfileCollection.ps1" `
+            -RadioToComputerDevice      "${{env.RADIO_TO_COMPUTER_DEVICE}}" `
+            -ComputerToRadioDevice      "${{env.COMPUTER_TO_RADIO_DEVICE}}" `
+            -MicrophoneToComputerDevice "${{env.MICROPHONE_TO_COMPUTER_DEVICE}}" `
+            -ComputerToSpeakerDevice    "${{env.COMPUTER_TO_SPEAKER_DEVICE}}"
 
     - name: Stash profile data
       uses: actions/upload-artifact@v7
diff --git a/ci/Invoke-PgoProfileCollection.ps1 b/ci/Invoke-PgoProfileCollection.ps1
new file mode 100644
index 00000000..7b2b2d4d
--- /dev/null
+++ b/ci/Invoke-PgoProfileCollection.ps1
@@ -0,0 +1,73 @@
+<#
+  .SYNOPSIS
+  Runs GeneratePGOProfiles.ps1 with an audio-endpoint pre-check, retrying a few
+  times.
+
+  .DESCRIPTION
+  On CI the virtual-cable audio endpoints (VB-Cable / VAC) intermittently fail to
+  be enumerable when FreeDV starts a UT -- sometimes not yet up when the job
+  begins, sometimes briefly dropping out mid-run right after SoX releases the
+  capture device. Either way FreeDV aborts with a fatal "device cannot be found"
+  message box.
+
+  This wrapper waits for the required endpoints (ci/Wait-AudioDevices.ps1, which
+  also restarts the audio stack), runs GeneratePGOProfiles.ps1, and retries the
+  whole thing a few times before giving up. Must be run from the folder
+  containing freedv.exe / GeneratePGOProfiles.ps1.
+
+  .PARAMETER Attempts
+  How many times to try the full collection. Default 3.
+#>
+param (
+    [Parameter(Mandatory = $true)] [string] $RadioToComputerDevice,
+    [Parameter(Mandatory = $true)] [string] $ComputerToRadioDevice,
+    [Parameter(Mandatory = $true)] [string] $MicrophoneToComputerDevice,
+    [Parameter(Mandatory = $true)] [string] $ComputerToSpeakerDevice,
+    [int] $Attempts = 3
+)
+
+$ErrorActionPreference = 'Stop'
+
+$waitScript = Join-Path $PSScriptRoot 'Wait-AudioDevices.ps1'
+
+for ($attempt = 1; $attempt -le $Attempts; $attempt++) {
+    Write-Host "=== GeneratePGOProfiles attempt $attempt/$Attempts ==="
+
+    # Playback (render) endpoints FreeDV emits to; recording (capture) endpoints
+    # FreeDV / SoX read from. "Line 1 (Virtual Audio Cable)" is used for both.
+    try {
+        & $waitScript `
+            -Playback  $ComputerToRadioDevice, $ComputerToSpeakerDevice `
+            -Recording $RadioToComputerDevice, $MicrophoneToComputerDevice `
+            -TimeoutSeconds 120
+    }
+    catch {
+        Write-Host "::warning::Audio endpoint wait failed on attempt ${attempt}: $_"
+    }
+
+    $rc = 1
+    try {
+        & .\GeneratePGOProfiles.ps1 `
+            -RadioToComputerDevice      $RadioToComputerDevice `
+            -ComputerToRadioDevice      $ComputerToRadioDevice `
+            -MicrophoneToComputerDevice $MicrophoneToComputerDevice `
+            -ComputerToSpeakerDevice    $ComputerToSpeakerDevice
+        $rc = $LASTEXITCODE
+    }
+    catch {
+        Write-Host "::warning::GeneratePGOProfiles threw on attempt ${attempt}: $_"
+        $rc = 1
+    }
+
+    if ($rc -eq 0) {
+        Write-Host "PGO data generated on attempt $attempt."
+        exit 0
+    }
+
+    Write-Host "::warning::GeneratePGOProfiles failed on attempt $attempt (exit $rc)."
+    # Drop any partial .profraw so the retry (and the upload) start clean.
+    Remove-Item -ErrorAction SilentlyContinue *.profraw
+}
+
+Write-Host "::error::GeneratePGOProfiles failed after $Attempts attempts."
+exit 1
diff --git a/ci/Wait-AudioDevices.ps1 b/ci/Wait-AudioDevices.ps1
new file mode 100644
index 00000000..1734152e
--- /dev/null
+++ b/ci/Wait-AudioDevices.ps1
@@ -0,0 +1,119 @@
+<#
+  .SYNOPSIS
+  Blocks until the named Windows audio endpoints are enumerable, or fails with
+  diagnostics after a timeout.
+
+  .DESCRIPTION
+  FreeDV enumerates audio devices through the Core Audio MMDevice API and aborts
+  with a fatal "device cannot be found" message box if a configured device is
+  missing when a test starts. On CI the virtual cables (VB-Cable / VAC) sometimes
+  take a while to expose their render / capture endpoints after the audio service
+  is (re)started, or briefly drop out of enumeration after another process
+  releases them -- which makes the PGO profile collection job fail intermittently.
+
+  This script polls "Get-AudioDevice -List" (from AudioDeviceCmdlets, the same
+  active-endpoint enumeration surface FreeDV uses) until every required endpoint
+  is present. It restarts the Windows audio stack once up front and once more
+  partway through as a nudge. On timeout it prints a full device dump and throws.
+
+  .PARAMETER Playback
+  Names of required playback (render) endpoints.
+
+  .PARAMETER Recording
+  Names of required recording (capture) endpoints.
+
+  .PARAMETER TimeoutSeconds
+  Total time to wait for all endpoints. Default 180.
+
+  .PARAMETER NoRestart
+  Do not restart the audio services (just poll).
+
+  .EXAMPLE
+  PS> ./ci/Wait-AudioDevices.ps1 `
+        -Playback  "Speakers (VB-Audio Virtual Cable)", "Line 1 (Virtual Audio Cable)" `
+        -Recording "CABLE Output (VB-Audio Virtual Cable)", "Line 1 (Virtual Audio Cable)"
+#>
+param (
+    [string[]] $Playback = @(),
+    [string[]] $Recording = @(),
+    [int] $TimeoutSeconds = 180,
+    [switch] $NoRestart
+)
+
+$ErrorActionPreference = 'Stop'
+
+if (-not (Get-Module -ListAvailable -Name AudioDeviceCmdlets)) {
+    Install-Module -Name AudioDeviceCmdlets -Force -Confirm:$false -Scope CurrentUser
+}
+Import-Module AudioDeviceCmdlets
+
+$Playback  = @($Playback  | Where-Object { $_ } | Select-Object -Unique)
+$Recording = @($Recording | Where-Object { $_ } | Select-Object -Unique)
+
+function Get-MissingEndpoints {
+    $devices   = Get-AudioDevice -List
+    $havePlay  = @($devices | Where-Object { $_.Type -eq 'Playback'  } | ForEach-Object { $_.Name })
+    $haveRec   = @($devices | Where-Object { $_.Type -eq 'Recording' } | ForEach-Object { $_.Name })
+
+    $missing = @()
+    foreach ($name in $Playback)  { if ($havePlay -notcontains $name) { $missing += "playback : $name" } }
+    foreach ($name in $Recording) { if ($haveRec  -notcontains $name) { $missing += "recording: $name" } }
+    return $missing
+}
+
+function Restart-AudioStack {
+    if ($NoRestart) { return }
+    Write-Host "Restarting Windows audio services (AudioEndpointBuilder, audiosrv)..."
+    # AudioEndpointBuilder owns endpoint enumeration; audiosrv depends on it and
+    # is restarted with it. -Force also restarts dependent services.
+    foreach ($svc in 'AudioEndpointBuilder', 'audiosrv') {
+        try   { Restart-Service -Name $svc -Force -ErrorAction Stop }
+        catch { Write-Host "  ($svc could not be restarted: $_)" }
+    }
+    Start-Sleep -Seconds 3
+}
+
+function Show-DeviceDump {
+    Write-Host "--- Get-AudioDevice -List ---"
+    Get-AudioDevice -List | Format-Table -AutoSize Index, Default, Type, Name | Out-String | Write-Host
+    Write-Host "--- Win32_SoundDevice ---"
+    Get-CimInstance Win32_SoundDevice | Format-Table -AutoSize Name, Status, StatusInfo | Out-String | Write-Host
+    Write-Host "--- AudioEndpoint PnP devices ---"
+    Get-PnpDevice -Class AudioEndpoint -ErrorAction SilentlyContinue |
+        Format-Table -AutoSize Status, FriendlyName | Out-String | Write-Host
+}
+
+Write-Host "Waiting up to $TimeoutSeconds s for audio endpoints:"
+$Playback  | ForEach-Object { Write-Host "  [playback ] $_" }
+$Recording | ForEach-Object { Write-Host "  [recording] $_" }
+
+Restart-AudioStack
+
+$deadline = (Get-Date).AddSeconds($TimeoutSeconds)
+$nudged   = $false
+$missing  = Get-MissingEndpoints
+
+while ($missing.Count -gt 0 -and (Get-Date) -lt $deadline) {
+    $remaining = ($deadline - (Get-Date)).TotalSeconds
+
+    if (-not $nudged -and $remaining -lt ($TimeoutSeconds / 2)) {
+        Write-Host "Still missing after half the timeout; nudging the audio stack:"
+        $missing | ForEach-Object { Write-Host "  $_" }
+        Restart-AudioStack
+        $nudged = $true
+    }
+
+    Start-Sleep -Seconds 3
+    $missing = Get-MissingEndpoints
+}
+
+if ($missing.Count -eq 0) {
+    Write-Host "All required audio endpoints are present."
+    Get-AudioDevice -List | Format-Table -AutoSize Index, Default, Type, Name | Out-String | Write-Host
+    exit 0
+}
+
+Write-Host "::error::Timed out waiting for audio endpoints; still missing:"
+$missing | ForEach-Object { Write-Host "  $_" }
+Show-DeviceDump
+throw "Required audio endpoints not available after $TimeoutSeconds s"
diff --git a/test/GeneratePGOProfiles.ps1 b/test/GeneratePGOProfiles.ps1
index 9b415abf..1454437b 100644
--- a/test/GeneratePGOProfiles.ps1
+++ b/test/GeneratePGOProfiles.ps1
@@ -51,6 +51,36 @@ param (
 
 $current_loc = Get-Location
 
+# Best-effort: wait for the configured audio endpoints to be enumerable before
+# starting FreeDV, so a virtual cable that has briefly dropped out of the
+# MMDevice list doesn't make the UT abort with a fatal "device cannot be found"
+# message box. The CI workflow does a stricter, failing check up front; this is
+# just a short guard against a mid-script drop between the TX and RX passes.
+function Wait-ForAudioDevices {
+    param (
+        [string[]] $Names,
+        [int] $TimeoutSeconds = 90
+    )
+
+    if (-not (Get-Module -ListAvailable -Name AudioDeviceCmdlets)) { return }
+    Import-Module AudioDeviceCmdlets -ErrorAction SilentlyContinue
+
+    $wanted = @($Names | Where-Object { $_ } | Select-Object -Unique)
+    $deadline = (Get-Date).AddSeconds($TimeoutSeconds)
+    while ($true) {
+        try { $have = @((Get-AudioDevice -List).Name) } catch { $have = @() }
+        $missing = @($wanted | Where-Object { $have -notcontains $_ })
+        if ($missing.Count -eq 0) { return }
+        if ((Get-Date) -ge $deadline) {
+            Write-Host "WARNING: audio device(s) still missing after ${TimeoutSeconds}s: $($missing -join ', ')"
+            return
+        }
+        Start-Sleep -Seconds 3
+    }
+}
+
+$allDevices = @($RadioToComputerDevice, $ComputerToRadioDevice, $MicrophoneToComputerDevice, $ComputerToSpeakerDevice)
+
 # Clone the RADE test corpus if not already present, then resample the TX test file to 48 kHz
 # to reduce CPU usage during the run.
 if (-not (Test-Path "$current_loc\rade_src")) {
@@ -91,6 +121,8 @@ $soxProcess.StartInfo = $soxPsi
 [void]$soxProcess.Start()
 
 # Start FreeDV in test mode to record TX
+Wait-ForAudioDevices -Names $allDevices
+
 $psi = New-Object System.Diagnostics.ProcessStartInfo
 $psi.CreateNoWindow = $true
 $psi.UseShellExecute = $false
@@ -121,6 +153,10 @@ try {
 }
 $soxProcess.WaitForExit()
 
+# Killing SoX above can briefly disturb the shared audio engine; make sure the
+# endpoints are back before the RX pass starts.
+Wait-ForAudioDevices -Names $allDevices
+
 $psi.Arguments = @("/f $quoted_conf_filename /ut rx /utmode RADEV1 /rxfile `"$current_loc\test.wav`" /rxfeaturefile `"$current_loc\rxfeatures.f32`"")
 
 $conf_tmpl = Get-Content "$current_loc\freedv-pgo.conf.tmpl"