A Windows Vista Service Pack 1-based guest virtual machine restarts without warning after you uninstall the RC1 integration services on a Windows Server 2008-based computer

Consider the following scenario:

• You have a Windows Server 2008-based computer that has Hyper-V installed.
• You are running a Windows Vista Service Pack 1 (SP1)-based guest virtual machine on the computer.
• You install the Release Candidate 0 (RC0) integration services on the guest virtual machine.
• You upgrade the guest virtual machine to use Release Candidate 1 (RC1) integration services.
• You uninstall RC1 integration services on the guest virtual machine.

In this scenario, the Windows Vista SP1 guest virtual machine restarts without any warning. Additionally, the following events are logged in the Hyper-V-Worker-Admin logs:

• Source: Microsoft-Windows-Hyper-V-Worker
  Date: 5/2/2008 11:46:31 AM
  Event ID: 12540
  Task Category: None
  Level: Critical
  Keywords:
  User: NETWORK SERVICE
  Description: 'RC Vista Ultimate SP1 x86' device Microsoft Synthetic Display Controller experienced a protocol error indicative of a deep system problem. (Virtual machine 921D5BB0-049B-4C13-96BC-923F9A53744A)

• Log Name: Microsoft-Windows-Hyper-V-Worker-Admin
  Source: Microsoft-Windows-Hyper-V-Worker
  Date: 5/2/2008 11:46:31 AM
  Event ID: 11902
  Task Category: None
  Level: Error
  Keywords:
  User: NETWORK SERVICE
  Description: 'RC Vista Ultimate SP1 x86' (Device 'Microsoft Synthetic Display Controller'): An unrecoverable internal error has occurred. (Virtual machine 921D5BB0-049B-4C13-96BC-923F9A53744A)

• Log Name: Microsoft-Windows-Hyper-V-Worker-Admin
  Source: Microsoft-Windows-Hyper-V-Worker
  Date: 5/2/2008 11:46:31 AM
  Event ID: 12070
  Task Category: None
  Level: Error
  Keywords:
  User: NETWORK SERVICE
  Description: 'RC Vista Ultimate SP1 x86' Microsoft Synthetic Video (Instance ID {F3CF6965-E8D3-44A9-9B7D-A04245EA7525}): Failed to pause with error 'Catastrophic failure' (0x8000FFFF). (Virtual machine 921D5BB0-049B-4C13-96BC-923F9A53744A)

This problem occurs because the driver that is used by the Microsoft Synthetic Display adapter reverts to the RC0 version when you uninstall the RC1 integration services. The RC0 version is incompatible with Hyper-V RC1.

To resolve this problem, use one of the following methods.

Method 1: Use the System Restore tool

1. Start the guest operating system in safe mode. To do this, follow these steps:
   1. Make sure that you remove any virtual floppy disks, CDs, and DVDs from the virtual machine.
   2. Start the virtual machine.
   3. Press and hold F8 key while virtual machine starts.
      
      Note You must press F8 key the Windows logo appears.
   4. In the Advanced Boot Options window, select the Safe Mode option, and then press ENTER.
   5. Log on to the computer again by using a user account that has the administrator rights.
2. Start the System Restore tool to restore the computer to an earlier date. To do this, follow these steps:
   1. Click Start , type system restore in the Start Search box, and then click System Restore in the Programs list. If you are prompted for an administrator password or for confirmation, type your password, or click Continue.
   2. In the System Restore dialog box, click Choose a different restore point, and then click Next.
   3. In the list of restore points, click a restore point that was created before you started to experience the problem, and then click Next.
   4. Click Finish.
   The computer restarts. The system files and settings revert to the state that they were in when the restore point was created.

Method 2: Uninstall the Hyper-V RC update

1. Start the guest operating system in safe mode. To do this, follow these steps:
   1. Make sure that you remove any virtual floppy disks, CDs, and DVDs from the virtual machine.
   2. Start the virtual machine.
   3. Press and hold F8 while the virtual machine starts.
      
      Note You must press F8 before the Windows logo appears.
   4. In the Advanced Boot Options window, select the Safe Mode option, and then press ENTER.
   5. Log on to the computer again by using a user account that has the administrator rights.
2. Uninstall the Hyper-V RC update. To do this, follow these steps:
   1. In Control Panel, click View Installed Updates in the Programs and Features item in the navigation pane.
   2. Click Update for Microsoft Windows (KB949757), and then click Uninstall.
   3. Restart the virtual machine to complete the installation process.

Method 3: Reinstall the Hyper-V RC1 integration services

1. Start the guest operating system in safe mode. To do this, follow these steps:
   1. Make sure that you remove any virtual floppy disks, CDs, and DVDs from the virtual machine.
   2. Start the virtual machine.
   3. Press and hold F8 while the virtual machine starts.
      
      Note You must press F8 before the Windows logo appears.
   4. In the Advanced Boot Options window, select the Safe Mode option, and then press ENTER.
   5. Log on to the computer again by using a user account that has the administrator rights.
2. Install the Hyper-V integration services. To do this, follow these steps:
   1. Open the Virtual Machine Connection in Hyper-V Manager.
   2. Select the Insert Integration Services Setup Disk option on the Action menu. Installation of the integration services starts automatically.
   3. Follow the installation instructions in the guest operating system to install the integration services.
   4. Restart the virtual machine to complete the installation process.