I’ve encountered a failure while upgrading my paravirtual (PV) drivers, or I’ve accidentally uninstalled my PV drivers and now I can’t connect to my instance.

If the PV drivers are corrupted or missing from your instance, you can reinstall them using the recommended method described at Method 1 – Enhanced Networking.

Alternatively, you can attach the boot volume of the inaccessible instance to a recovery instance, set up automatic login with an administrator account, and then silently run the PV driver installation at next boot.

1.    Stop the inaccessible instance.

2.    After the instance is stopped, create an Amazon EBS-backed Amazon Machine Image (AMI) by selecting the instance in the Amazon Elastic Compute Cloud (Amazon EC2) console, opening the Actions menu, and then choosing Image > Create Image.

3.    Launch a Windows Server 2008 R2 instance in the same AWS Region and Availability Zone as the inaccessible instance. You’ll use this new instance as the “recovery” instance, and you can terminate it after the following steps are completed and your original instance is healthy again.

Note: If your recovery instance is based on the same AMI that the original instance is based on, and the operating system is later than Windows Server 2003, you must repair the disk signature collision by following step 7 as described at Waiting for the metadata service, or restore a new volume from the EBS snapshot and then select a different Windows AMI for the temporary instance.

4.    Detach the boot volume of the inaccessible instance.

5.    Attach the volume to the recovery instance using the default device mapping suggested by the EC2 console.

6.    Connect to the recovery instance through Remote Desktop Protocol (RDP).

7.    On the recovery instance, download and extract the latest version of the AWS PV Drivers.

8.    Copy AWSPVDriverSetup.msi to the root of the newly attached volume. Usually, this is the D: drive. If not, be sure to substitute the correct drive letter for the D: in the first command in the next step.

9.    Open a command prompt and run the following commands, replacing the bold placeholder values:

Note: To perform these commands, you must have administrator permissions, and you must use either a local account or a domain account with cached credentials.

reg load HKLM\AWSTempSoftware D:\Windows\System32\config\SOFTWARE
reg add HKLM\AWSTempSoftware\Microsoft\Windows\CurrentVersion\RunOnce /t REG_SZ /v 1 /d "reg delete \"HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\" /v AutoAdminLogon /f"
reg add HKLM\AWSTempSoftware\Microsoft\Windows\CurrentVersion\RunOnce /t REG_SZ /v 2 /d "reg delete \"HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\" /v DefaultDomainName /f
reg add HKLM\AWSTempSoftware\Microsoft\Windows\CurrentVersion\RunOnce /t REG_SZ /v 3 /d "reg delete \"HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\" /v DefaultPassword /f
reg add HKLM\AWSTempSoftware\Microsoft\Windows\CurrentVersion\RunOnce /t REG_SZ /v 4 /d "reg delete \"HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\" /v DefaultUserName /f
reg add HKLM\AWSTempSoftware\Microsoft\Windows\CurrentVersion\RunOnce /t REG_SZ /v 5 /d "msiexec /i C:\AWSPVDriverSetup.msi /passive /forcerestart"
reg add "HKLM\AWSTempSoftware\Microsoft\Windows NT\CurrentVersion\Winlogon" /v DefaultUserName /t REG_SZ /d "Administrator_Account_Name"
reg add "HKLM\AWSTempSoftware\Microsoft\Windows NT\CurrentVersion\Winlogon" /v DefaultPassword /t REG_SZ /d "Administrator_Password"
reg add "HKLM\AWSTempSoftware\Microsoft\Windows NT\CurrentVersion\Winlogon" /v DefaultDomainName /t REG_SZ /d "Domain_Or_Computer_Name"
reg add "HKLM\AWSTempSoftware\Microsoft\Windows NT\CurrentVersion\Winlogon" /v AutoAdminLogon /t REG_SZ /d 1
reg unload HKLM\AWSTempSoftware

10.    Detach the secondary volume from the recovery instance.

11.    Attach the volume to the inaccessible instance by using the device mapping /dev/sda1.

12.    Start the inaccessible instance.

13.    Wait for the instance to boot, perform the automatic login and installation, reboot, and then wait several minutes for the instance to pass status checks. You can monitor the process more closely by using instance console screenshots.

To confirm that Windows booted successfully on your instance, check the instance’s console output for the message Windows is ready to use.

To confirm that your selected PV driver was installed correctly, check the instance’s console output for the line that begins with Driver: AWS PV Storage Host Adapter, and confirm that the version shown matches the version you installed.


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Published: 2016-11-21

Updated: 2018-09-24