Azure VM startup is stuck at Windows update

This article helps resolve the issue when your Virtual Machine (VM) is stuck at the Windows Update stage during startup.

Symptom

A Windows VM doesn't start. When you check the screenshots in the Boot diagnostics window, you see that the startup is stuck in the update process. The following are examples of messages that you may receive:

• Installing Windows ##% Don't turn off your PC. This will take a while Your PC will restart several times
• Keep your PC on until this is done. Installing update # of #...
• We couldn't complete the updates Undoing changes Don't turn off your computer
• Failure configuring Windows updates Reverting changes Do not turn off your computer
• Error < error code > applying update operations ##### of ##### (\Regist...)
• Fatal Error < error code > applying update operations ##### of ##### ($$...)

Solution

 Tip

If you have a recent backup of the VM, you may try restoring the VM from the backup to fix the boot problem.

Depending on the number of updates that are getting installed or rolled backing, the update process can take a while. Leave the VM in this state for 8 hours. If the VM is still in this state after that period, restart the VM from the Azure portal, and see if it can start normally. If this step doesn't work, try the following solution.

Remove the update that causes the problem

1. Take a snapshot of the OS disk of the affected VM as a backup. For more information, see Snapshot a disk.

2. Attach the OS disk to a recovery VM.

3. Once the OS disk is attached on the recovery VM, run diskmgmt.msc to open Disk Management, and ensure the attached disk is ONLINE. Take note of the drive letter that is assigned to the attached OS disk holding the \windows folder. If the disk is encrypted, decrypt the disk before proceeding with next steps in this document.

4. Open an elevated command prompt instance (Run as administrator). Run the following command to get the list of the update packages that are on the attached OS disk:

   ConsoleCopy

    

   dism /image:<Attached OS disk>:\ /get-packages > c:\temp\Patch_level.txt
   

   For example, if the attached OS disk is drive F, run the following command:

   ConsoleCopy

    

   dism /image:F:\ /get-packages > c:\temp\Patch_level.txt
   

5. Open the C:\temp\Patch_level.txt file, and then read it from the bottom up. Locate the update that's in Install Pending or Uninstall Pending state. The following is a sample of the update status:

   Copy

    

   Package Identity : Package_for_RollupFix~31bf3856ad364e35~amd64~~17134.345.1.5
   State : Install Pending
   Release Type : Security Update
   Install Time :
   

6. Remove the update that caused the problem:

   Copy

    

   dism /Image:<Attached OS disk>:\ /Remove-Package /PackageName:<PACKAGE NAME TO DELETE>
   

   Example:

   Copy

    

   dism /Image:F:\ /Remove-Package /PackageName:Package_for_RollupFix~31bf3856ad364e35~amd64~~17134.345.1.5
   

    Note

   Depending on the size of the package, the DISM tool will take a while to process the un-installation. Normally the process will be completed within 16 minutes.

7. Detach the OS disk and recreate the VM. Then check whether the issue is resolved.