Your computer may freeze or it may restart to a black screen that has an 0xc0000034 error message after you install a Windows Vista service pack

You install a Windows Vista service pack on your computer. After the service pack is installed, the computer may freeze, or it may restart. If the computer restarts, you see an error message that resembles the following on a black screen: Note If you restart the computer, you experience the same error message.

To resolve this issue, use the following methods starting with Method 1. If Method 1 does not resolve the issue, try Method 2. We recommend that you try Method 3 only if you are an advanced user.

These methods are intended to help you return your computer to a bootable state without the service pack installed. After you successfully return your computer to a bootable state, you should try to install the service pack again.

Note The following methods require the Windows Vista DVD. If your computer manufacturer did not supply a Windows Vista DVD, you may be able to start to Repair tools. To do this, follow these steps:

1. Restart your computer, and then press F8 during the restart process to open the Advanced Boot Options menu. Or, wait for and select the Advanced Options Menu option.
2. Select the option on the menu to repair your computer.
3. Select Administrator, and then press ENTER.
4. Go to step 4 in Method 1 or Method 2.

Method 1: Restore your computer to an earlier point in time by using System Restore

System Restore will restore your computer to an earlier point in time before you experienced this issue and then it will restart your computer. To restore your system, follow these steps:

1. Insert the Windows Vista DVD in the DVD drive, and then restart your computer from the DVD.
   
   Note When you receive the prompt Press any Key to boot from the CD or DVD, press any key on the keyboard to restart your computer by using the Windows Vista DVD.
2. Select your language setting, and then click Next.
3. Select Repair your computer.
4. Select the Windows Vista installation to be repaired, and then click Next.
5. Under System Recovery Options, select System Restore, and then press ENTER.
   
   Note If the repair process detects a problem when it starts Windows Vista, it will run Startup Repair to automatically fix the problem. If this occurs, click Cancel, and then click View Advanced Options for system recovery and support.
6. In the System Restore Wizard, click Next.
7. Select the Restore Point that has a date before the date you received the error message, and then click Next.
   
   Note In most cases, this is the latest Restore Point in the list.
8. Click Next.
9. Click Finish. System Restore will finish and restart your computer.
   
   Note If you see the black screen and the same or a similar error message, you may have to repeat these steps and restore your computer to an earlier date.

Method 2: Use Startup Repair to try to repair any startup issues with your computer

Startup Repair will try to repair any startup issues in Windows Vista. To run the Startup Repair tool, follow these steps:

1. Insert the Windows Vista DVD in the DVD drive, and then restart your computer from the DVD.
   
   Note When you receive the prompt Press any Key to boot from the CD or DVD, press any key on the keyboard to restart your computer by using the Windows Vista DVD.
2. Select your language setting, and then click Next.
3. Select Repair your computer.
4. Select the Windows Vista installation to be repaired, and then click Next.
5. Under System Recovery Options, select Startup Repair, and then press ENTER.
   
   Note If the repair process detects a problem when it starts Windows Vista, it will run Startup Repair to automatically fix the problems. If this occurs, click Cancel, and then click View Advanced Options for system recovery and support.
6. Click Finish when the Startup Repair has finished.
7. Under System Recovery Options, click Restart.
   
   Note If you see a black screen that has the same error message, try Method 3.

Method 3: Delete the poqexec entry from the SetupExecute value (advanced users only)

Note We recommend that you try Method 3 only if you are an advanced user.

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base: To delete the poqexec entry from the SetupExecute (REG_MULTI_SZ) value, you must clear the value. To do this, follow these steps:

1. Insert the Windows Vista DVD in the DVD drive, and then restart your computer from the DVD.
   
   Note When you receive the prompt Press any Key to boot from the CD or DVD, press any key on the keyboard to restart your computer by using the Windows Vista DVD.
2. Select your language setting, and then click Next.
3. Select Repair your computer.
   
   Note If you are prompted to do a System Restore, select No, and then press ENTER.
4. Under System Recovery Options, select Startup Repair, and then press ENTER.
   
   Note If the repair process detects a problem when it starts Windows Vista, it will run Startup Repair to automatically fix the problems. If this occurs, click Cancel, and then click View Advanced Options for system recovery and support.
5. Under System Recovery Options, select Command Prompt, and then press ENTER.
6. At the command prompt, type the following commands, and then press ENTER after each command:
   Reg load HKLM\BaseSystem C:\Windows\System32\config\SYSTEM
   
   Reg Delete "HKLM\BaseSystem\CurrentControlSet\Control\Session Manager" /v SetupExecute
   
   Reg add "HKLM\BaseSystem\CurrentControlSet\Control\Session Manager" /v SetupExecute /t REG_MULTI_SZ
7. At the command prompt, type exit, and then press ENTER.
8. Restart your computer.