Issue/Introduction

QGA depends on the VirtIO Serial channel. If a driver is not loaded correctly or a migration/P2V leaves a driver conflict, the platform might be unable to establish the channel and show VMTools as not installed even after the VMTools installer completes.

Symptoms

• VMTools installation completes, but the UI still shows it as not installed.
• VirtIO Serial Driver and Balloon Driver show yellow warning icons in Device Manager.
• Driver status is the key evidence that distinguishes this issue from an empty VERSION file, Defender quarantine, or a status that has simply not refreshed.

Environment

• Verified on a Windows guest in ZSphere 4.10.25.
• The typical context for TIC-5001 is residual Windows drivers after migration/P2V.

Possible causes

First identify the abnormal device and its error code, and then check the driver provider/version and migration history. Follow this article only when both an abnormal device and a QGA status problem are present.

Issue classification

• Type: Environment/driver compatibility issue.
• Known issue: Yes. TIC-6202 is Closed/Done; see also TIC-5001, Closed/Won't Do.
• Root cause: An abnormal Windows VirtIO Serial/Balloon driver or a residual-driver conflict after migration prevents the QGA channel from working normally.
• Affected version: TIC-6202 was verified on ZSphere 4.10.25; this is not a proven defect in all versions.
• Confidence: High, provided that the device error code and channel failure are both present.

Resolution

Check 1: Enumerate abnormal devices

• Read-only PowerShell:

  Get-PnpDevice -PresentOnly | Where-Object { $_.Status -ne 'OK' } |
    Format-Table Status,Class,FriendlyName,InstanceId -Auto

• If the output includes VirtIO Serial/Balloon: Continue to check the error code and driver.
• If there is no related abnormal device: Return to KB-100553 and select another branch.

Check 2: Read device errors and driver versions

• Read-only PowerShell:

  Get-CimInstance Win32_PnPEntity |
    Where-Object { $_.Name -match 'VirtIO|Balloon|Serial' } |
    Select-Object Name,Status,ConfigManagerErrorCode,PNPDeviceID
  Get-CimInstance Win32_PnPSignedDriver |
    Where-Object { $_.DeviceName -match 'VirtIO|Balloon|Serial' } |
    Select-Object DeviceName,DriverProviderName,DriverVersion,DriverDate

• If ErrorCode is nonzero and the driver version is abnormal or residual: The driver-path evidence is sufficient.
• If ErrorCode is 0: The warning might have cleared or the screenshot might be outdated. Refresh the evidence before updating the driver.

Check 3: Check the QGA service

• Read-only PowerShell:

  Get-Service | Where-Object { $_.Name -match 'qemu|guest' } |
    Format-Table Name,Status,StartType -Auto

• If the service exists, VirtIO Serial is abnormal, and the platform channel is unavailable: The causal chain in this article applies.
• If the service or installation directory is absent: The installation might be incomplete; do not attribute the issue to a driver conflict.

Recommended actions

During a maintenance window, a Windows administrator must create a backup or system restore point, update the abnormal device using the VirtIO driver that matches the target Windows version and ZSphere VMTools, and then restart the guest according to the approved plan. If the update fails, roll back the driver or restore the snapshot. After restart, verify device ErrorCode=0, the QGA service, and the page status.

Long-term solution

Remove incompatible drivers before migration/P2V, maintain a Windows-to-VirtIO-driver compatibility matrix, and automatically check critical device status after VMTools installation.

Additional information

When to escalate

• You are unsure whether the driver package matches the Windows version.
• The production guest cannot be restarted.
• The page still shows VMTools as not installed after the driver recovers.
• Code-signing, blue-screen, or security software alerts are present.

Information to collect

ZSphere/Windows versions, whether migration/P2V was performed, Device Manager screenshots, device error codes, driver provider/version/date, QGA service status, and VMTools installation logs.

Related issues

• TIC-6202, Closed/Done.
• TIC-5001, Closed/Won't Do.
• Jira status verified on 2026-08-06.