Troubleshoot issues connecting to your Amazon EC2 Windows instance - Amazon Elastic Compute Cloud
Remote Desktop can't connect to the remote computerError using the macOS RDP clientRDP displays a black screen instead of the desktopUnable to remotely log on to an instance with a user that is not an administrator Troubleshooting Remote Desktop issues using AWS Systems ManagerEnable Remote Desktop on an EC2 instance with remote registryI've lost my private key. How can I connect to my Windows instance?

Troubleshoot issues connecting to your Amazon EC2 Windows instance

The following information and common errors can help you troubleshoot issues when connecting to your Windows instance.

Remote Desktop can't connect to the remote computer

Try the following to resolve issues related to connecting to your instance:

  • Verify that you're using the correct public DNS hostname. (In the Amazon EC2 console, select the instance and check Public DNS (IPv4) in the details pane.) If your instance is in a VPC and you do not see a public DNS name, you must enable DNS hostnames. For more information, see DNS attributes for your VPC in the Amazon VPC User Guide.

  • Verify that your instance has a public IPv4 address. If not, you can associate an Elastic IP address with your instance. For more information, see Elastic IP addresses.

  • To connect to your instance using an IPv6 address, check that your local computer has an IPv6 address and is configured to use IPv6. For more information, see Configure IPv6 on your instances in the Amazon VPC User Guide.

  • Verify that your security group has a rule that allows RDP access on port 3389.

  • If you copied the password but get the error Your credentials did not work, try typing them manually when prompted. It's possible that you missed a character or got an extra white space character when you copied the password.

  • Verify that the instance has passed status checks. For more information, see Status checks for Amazon EC2 instances and Troubleshoot Amazon EC2 Linux instances with failed status checks.

  • Verify that the route table for the subnet has a route that sends all traffic destined outside the VPC to the internet gateway for the VPC. For more information, see Creating a custom route table (Internet Gateways) in the Amazon VPC User Guide.

  • Verify that Windows Firewall, or other firewall software, is not blocking RDP traffic to the instance. We recommend that you disable Windows Firewall and control access to your instance using security group rules. You can use AWSSupport-TroubleshootRDP to disable the Windows Firewall profiles using SSM Agent . To disable Windows Firewall on a Windows instance that is not configured for AWS Systems Manager, use AWSSupport-ExecuteEC2Rescue, or use the following manual steps:

  1. Stop the affected instance and detach its root volume.

  2. Launch a temporary instance in the same Availability Zone as the affected instance.

    Warning

    If your temporary instance is based on the same AMI that the original instance is based on, you must complete additional steps or you won't be able to boot the original instance after you restore its root volume because of a disk signature collision. Alternatively, select a different AMI for the temporary instance. For example, if the original instance uses the AWS Windows AMI for Windows Server 2016, launch the temporary instance using the AWS Windows AMI for Windows Server 2019.

  3. Attach the root volume from the affected instance to this temporary instance. Connect to the temporary instance, open the Disk Management utility, and bring the drive online.

  4. Open Regedit and select HKEY_LOCAL_MACHINE. From the File menu, choose Load Hive. Select the drive, open the file Windows\System32\config\SYSTEM, and specify a key name when prompted (you can use any name).

  5. Select the key you just loaded and navigate to ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy. For each key with a name of the form xxxxProfile, select the key and change EnableFirewall from 1 to 0. Select the key again, and from the File menu, choose Unload Hive.

  6. (Optional) If your temporary instance is based on the same AMI that the original instance is based on, you must complete the following steps or you won't be able to boot the original instance after you restore its root volume because of a disk signature collision.

    Warning

    The following procedure describes how to edit the Windows Registry using Registry Editor. If you are not familiar with the Windows Registry or how to safely make changes using Registry Editor, see Configure the Registry.

    1. Open a command prompt, type regedit.exe, and press Enter.

    2. In the Registry Editor, choose HKEY_LOCAL_MACHINE from the context menu (right-click), and then choose Find.

    3. Type Windows Boot Manager and then choose Find Next.

    4. Choose the key named 11000001. This key is a sibling of the key you found in the previous step.

    5. In the right pane, choose Element and then choose Modify from the context menu (right-click).

    6. Locate the four-byte disk signature at offset 0x38 in the data. Reverse the bytes to create the disk signature, and write it down. For example, the disk signature represented by the following data is E9EB3AA5:

      ...
0030  00 00 00 00 01 00 00 00
0038  A5 3A EB E9 00 00 00 00
0040  00 00 00 00 00 00 00 00
...

    7. In a Command Prompt window, run the following command to start Microsoft DiskPart.

      diskpart

    8. Run the following DiskPart command to select the volume. (You can verify that the disk number is 1 using the Disk Management utility.)

      DISKPART> select disk 1

Disk 1 is now the selected disk.

    9. Run the following DiskPart command to get the disk signature.

      DISKPART>  uniqueid disk

Disk ID: 0C764FA8

    10. If the disk signature shown in the previous step doesn't match the disk signature from BCD that you wrote down earlier, use the following DiskPart command to change the disk signature so that it matches:

      DISKPART> uniqueid disk id=E9EB3AA5

  7. Using the Disk Management utility, bring the drive offline.

    Note

    The drive is automatically offline if the temporary instance is running the same operating system as the affected instance, so you won't need to bring it offline manually.

  8. Detach the volume from the temporary instance. You can terminate the temporary instance if you have no further use for it.

  9. Restore the root volume of the affected instance by attaching it as /dev/sda1.

  10. Start the instance.

Error using the macOS RDP client

If you are connecting to a Windows Server instance using the Remote Desktop Connection client from the Microsoft website, you may get the following error:

Remote Desktop Connection cannot verify the identity of the computer that you want to connect to.

Download the Microsoft Remote Desktop app from the Mac App Store and use the app to connect to your instance.

RDP displays a black screen instead of the desktop

Try the following to resolve this issue:

  • Check the console output for additional information. To get the console output for your instance using the Amazon EC2 console, select the instance, and then choose Actions, Monitor and troubleshoot, Get system log.

  • Verify that you are running the latest version of your RDP client.

  • Try the default settings for the RDP client. For more information, see Remote Session Environment.

  • If you are using Remote Desktop Connection, try starting it with the /admin option as follows.

    mstsc /v:instance /admin

  • If the server is running a full-screen application, it might have stopped responding. Use Ctrl+Shift+Esc to start Windows Task Manager, and then close the application.

  • If the server is over-utilized, it might have stopped responding. To monitor the instance using the Amazon EC2 console, select the instance and then select the Monitoring tab. If you need to change the instance type to a larger size, see Amazon EC2 instance type changes.

Unable to remotely log on to an instance with a user that is not an administrator

If you are not able to remotely log on to a Windows instance with a user that is not an administrator account, ensure that you have granted the user the right to log on locally. See Grant a user or group the right to log on locally to the domain controllers in the domain.

Troubleshooting Remote Desktop issues using AWS Systems Manager

You can use AWS Systems Manager to troubleshoot issues connecting to your Windows instance using RDP.

AWSSupport-TroubleshootRDP

The AWSSupport-TroubleshootRDP automation document allows the user to check or modify common settings on the target instance that can impact Remote Desktop Protocol (RDP) connections, such as the RDP Port, Network Layer Authentication (NLA), and Windows Firewall profiles. By default, the document reads and outputs the values of these settings.

The AWSSupport-TroubleshootRDP automation document can be used with EC2 instances, on-premises instances, and virtual machines (VMs) that are enabled for use with AWS Systems Manager (managed instances). In addition, it can also be used with EC2 instances for Windows Server that are not enabled for use with Systems Manager. For information about enabling instances for use with AWS Systems Manager, see Managed nodes in the AWS Systems Manager User Guide.

To troubleshoot using the AWSSupport-TroubleshootRDP document

  1. Log in to the Systems Manager Console.

  2. Verify that you are in the same Region as the impaired instance.

  3. Choose Documents from the left navigation pane.

  4. On the Owned by Amazon tab, enter AWSSupport-TroubleshootRDP in the search field. When the AWSSupport-TroubleshootRDP document appears, select it.

  5. Choose Execute automation.

  6. For Execution Mode, choose Simple execution.

  7. For Input parameters, InstanceId, enable Show interactive instance picker.

  8. Choose your Amazon EC2 instance.

  9. Review the examples, then choose Execute.

  10. To monitor the execution progress, for Execution status, wait for the status to change from Pending to Success. Expand Outputs to view the results. To view the output of individual steps, in Executed Steps, choose an item from Step ID.

AWSSupport-TroubleshootRDP examples

The following examples show you how to accomplish common troubleshooting tasks using AWSSupport-TroubleshootRDP. You can use either the example AWS CLI start-automation-execution command or the provided link to the AWS Management Console.

Example: Check the current RDP status

AWS CLI:

aws ssm start-automation-execution --document-name "AWSSupport-TroubleshootRDP" --parameters "InstanceId=instance_id, Action=Custom" --region region_code

AWS Systems Manager console:

https://console.aws.amazon.com/systems-manager/automation/execute/AWSSupport-TroubleshootRDP?region=region#documentVersion=$LATEST
Example: Disable the Windows Firewall

AWS CLI:

aws ssm start-automation-execution --document-name "AWSSupport-TroubleshootRDP" --parameters "InstanceId=instance_id, Action=Custom, Firewall=Disable" --region region_code

AWS Systems Manager console:

https://console.aws.amazon.com/systems-manager/automation/execute/AWSSupport-TroubleshootRDP?region=region_code#documentVersion=$LATEST&Firewall=Disable
Example: Disable Network Level Authentication

AWS CLI:

aws ssm start-automation-execution --document-name "AWSSupport-TroubleshootRDP" --parameters "InstanceId=instance_id, Action=Custom, NLASettingAction=Disable" --region region_code

AWS Systems Manager console:

https://console.aws.amazon.com/systems-manager/automation/execute/AWSSupport-TroubleshootRDP?region=region_code#documentVersion
Example: Set RDP Service Startup Type to Automatic and start the RDP service

AWS CLI:

aws ssm start-automation-execution --document-name "AWSSupport-TroubleshootRDP" --parameters "InstanceId=instance_id, Action=Custom, RDPServiceStartupType=Auto, RDPServiceAction=Start" --region region_code

AWS Systems Manager console:

https://console.aws.amazon.com/systems-manager/automation/execute/AWSSupport-TroubleshootRDP?region=region_code#documentVersion=$LATEST&RDPServiceStartupType=Auto&RDPServiceAction=Start
Example: Restore the default RDP Port (3389)

AWS CLI:

aws ssm start-automation-execution --document-name "AWSSupport-TroubleshootRDP" --parameters "InstanceId=instance_id, Action=Custom, RDPPortAction=Modify" --region region_code

AWS Systems Manager console:

https://console.aws.amazon.com/systems-manager/automation/execute/AWSSupport-TroubleshootRDP?region=region_code#documentVersion=$LATEST&RDPPortAction=Modify
Example: Allow remote connections

AWS CLI:

aws ssm start-automation-execution --document-name "AWSSupport-TroubleshootRDP" --parameters "InstanceId=instance_id, Action=Custom, RemoteConnections=Enable" --region region_code

AWS Systems Manager console:

https://console.aws.amazon.com/systems-manager/automation/execute/AWSSupport-TroubleshootRDP?region=region_code#documentVersion=$LATEST&RemoteConnections=Enable

AWSSupport-ExecuteEC2Rescue

The AWSSupport-ExecuteEC2Rescue automation document uses EC2Rescue for Windows Server to automatically troubleshoot and restore EC2 instance connectivity and RDP issues. For more information, see Run the EC2Rescue tool on unreachable instances.

The AWSSupport-ExecuteEC2Rescue automation document requires a stop and restart of the instance. Systems Manager Automation stops the instance and creates an Amazon Machine Image (AMI). Data stored in instance store volumes is lost. The public IP address changes if you are not using an Elastic IP address. For more information, see Run the EC2Rescue tool on unreachable instances in the AWS Systems Manager User Guide.

To troubleshoot using the AWSSupport-ExecuteEC2Rescue document

  1. Open the Systems Manager console.

  2. Verify that you are in the same Region as the impaired Amazon EC2 instance.

  3. In the navigation panel, choose Documents.

  4. Search for and select the AWSSupport-ExecuteEC2Rescue document, and then choose Execute automation.

  5. In Execution Mode, choose Simple execution.

  6. In the Input parameters section, for UnreachableInstanceId, enter the Amazon EC2 instance ID of the unreachable instance.

  7. (Optional) For LogDestination, enter the Amazon Simple Storage Service (Amazon S3) bucket name if you want to collect operating system logs for troubleshooting your Amazon EC2 instance. Logs are automatically uploaded to the specified bucket.

  8. Choose Execute.

  9. To monitor the execution progress, in Execution status, wait for the status to change from Pending to Success. Expand Outputs to view the results. To view the output of individual steps, in Executed Steps, choose the Step ID.

Enable Remote Desktop on an EC2 instance with remote registry

If your unreachable instance is not managed by AWS Systems Manager Session Manager, then you can use remote registry to enable Remote Desktop.

  1. From the EC2 console, stop the unreachable instance.

  2. Detach the root volume of the unreachable instance and attach it to a reachable instance in the same Availability Zone as a storage volume. If you don't have a reachable instance in the same Availability Zone, launch one. Note the device name of the root volume on the unreachable instance.

  3. On the reachable instance, open Disk Management. You can do so by running the following command in the Command Prompt window.

    diskmgmt.msc

  4. Right click the newly attached volume that came from the unreachable instance, and then choose Online.

  5. Open the Windows Registry Editor. You can do so by running the following command in the Command Prompt window.

    regedit

  6. In Registry Editor, choose HKEY_LOCAL_MACHINE, then select File, Load Hive.

  7. Select the drive of the attached volume, navigate to \Windows\System32\config\, select SYSTEM, and then choose Open.

  8. For Key Name, enter a unique name for the hive and choose OK.

  9. Back up the registry hive before making any changes to the registry.

    1. In the Registry Editor console tree, select the hive that you loaded: HKEY_LOCAL_MACHINE\your-key-name.

    2. Choose File, Export.

    3. In the Export Registry File dialog box, choose the location to which you want to save the backup copy, and then type a name for the backup file in the File name field.

    4. Choose Save.

  10. In Registry Editor, navigate to HKEY_LOCAL_MACHINE\your key name\ControlSet001\Control\Terminal Server, and then, in the details pane, double-click fDenyTSConnections.

  11. In the Edit DWORD value box, enter 0 in the Value data field.

  12. Choose OK.

    Note

    If the value in the Value data field is 1, then the instance will deny remote desktop connections. A value of 0 allows remote desktop connections.

  13. In Registry Editor, choose HKEY_LOCAL_MACHINE\your-key-name, then select File, Unload Hive.

  14. Close Registry Editor and Disk Management.

  15. From the EC2 console, detach the volume from the reachable instance and then reattach it to the unreachable instance. When attaching the volume to the unreachable instance, enter the device name that you saved earlier in the device field.

  16. Restart the unreachable instance.

I've lost my private key. How can I connect to my Windows instance?

When you connect to a newly-launched Windows instance, you decrypt the password for the Administrator account using the private key for the key pair that you specified when you launched the instance.

If you lose the Administrator password and you no longer have the private key, you must reset the password or create a new instance. For more information, see Reset the Windows administrator password for an Amazon EC2 Windows instance. For steps to reset the password using an Systems Manager document, see Reset passwords and SSH keys on EC2 instances in the AWS Systems Manager User Guide.