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Why Can't I Log In to My Windows ECS?

Updated at: Sep 02, 2021 GMT+08:00

Symptom

A Windows ECS cannot be logged in to due to some reasons. For example, the network is abnormal, the firewall does not allow access to the local port for accessing the remote desktop, or the ECS vCPUs are overloaded.

This section describes how to troubleshoot the login failures on a Windows ECS.

If you cannot log in to your Windows ECS, follow the instructions provided in Login Using VNC on the Management Console. Then, locate the login fault by referring to Fault Locating.

Login Using VNC on the Management Console

Check whether you can log in to the ECS using VNC on the management console.

See What Are the Login Requirements for ECSs? to learn the requirements for logging in to an ECS.

  1. Log in to the management console.
  2. Under Compute, click Elastic Cloud Server.
  3. In the Operation column of the target ECS, click Remote Login.
    Figure 1 Remote Login
  4. (Optional) When the system displays "Press CTRL+ALT+DELETE to log on", click Ctrl+Alt+Del in the upper part of the remote login page to log in to the ECS.
    Figure 2 Ctrl+Alt+Del

For details about common VNC login issues, see Logins Through the Management Console.

If the login using VNC fails after the preceding operations are performed, record your resources and the time when the fault occurred. Then, click Service Tickets in the upper right corner of the management console, choose Create Service Ticket, and submit a ticket.

Fault Locating

If you can log in to the ECS using VNC but cannot log in to the ECS using a remote desktop connection, locate the fault as follows:

The following fault causes are sequenced based on their occurrence probability.

If the fault persists after you have ruled out a cause, check other causes.

Figure 3 Fault locating
Table 1 Possible causes and solutions

Possible Cause

Solution

The ECS is frozen or stopped.

Make sure that the ECS is in the Running state. For details, see Checking the ECS Status.

The entered username or password is incorrect.

The default username for Windows ECSs is Administrator. If the password is incorrect, reset the password using the password reset function on the management console. For details, see Checking the Login Mode.

The ECS is overloaded.

If the bandwidth or CPU usage of the ECS is excessively high, login failures may occur. For details, see Checking Whether the ECS Is Overloaded.

No EIP is bound to the ECS.

To log in to your ECS using RDP or MSTSC, ensure that the ECS has an EIP bound. For details, see Verifying that the ECS Has an EIP Bound.

The access is blocked by the Internet service provider (ISP).

Check whether you can access the ECS using another hotspot or network. For details, see Checking Whether the Network Is Functional.

The access is blocked by the firewall.

Disable the firewall and try again. For details, see Checking Whether the Firewall Is Correctly Configured.

The remote login port has been disabled in the security group or on the ECS.

Check whether the security group and the ECS allow traffic on the remote login port. For details, see Checking Whether the Remote Access Port Is Correctly Configured.

An IP address whitelist for SSH logins has been configured.

Check whether an SSH login IP address whitelist is configured in HSS. For details, see Checking the IP Address Allowlist for SSH Logins (with HSS Enabled).

The remote desktop protocol has been disabled on the ECS.

Make sure that the remote desktop protocol has been enabled on the ECS (only required for RDP and MSTSC logins). For details, see Checking the Remote Desktop Protocol on the ECS.

The access is blocked by third-party antivirus software.

Disable or uninstall the third-party antivirus software and try again. For details, see Checking Whether the Access Is Blocked by Antivirus Software.

The cause is displayed in the error message.

If an error message is displayed during remote login, check the operation guide based on the error information. For details, see Checking Whether an Error Occurred During a Remote Login.

Checking the ECS Status

Check whether the ECS is in the Running state on the management console. If the ECS is stopped, start it and try to log in to the ECS again.

Figure 4 Checking the ECS status

Checking the Login Mode

Check the login mode you set when you created the ECS.

Figure 5 Login Mode
  • Password: Check whether the login password is correct. If you forgot your password, reset the password. After you reset the password, restart the ECS for the new password to take effect.
  • Key pair: If your ECS is authenticated using a key pair, parse the private key file to obtain a password.
    1. Locate the target ECS.
    2. In the Operation column, click More and select Get Password.
    3. Copy the content of the private key file and paste it into the text box. Click Get Password to obtain a new random password.
  • Set password later: If you did not set a login mode when you create an ECS, you can use the password reset function (available in the Operation column of the target ECS) to obtain the login password after the ECS is created. After you reset the password, restart the ECS for the new password to take effect.

Checking Whether the ECS Is Overloaded

If the bandwidth or CPU usage of the ECS is excessively high, login failures may occur.

If you have created an alarm rule using Cloud Eye, the system automatically sends an alarm to you when the bandwidth or CPU usage reaches the threshold specified in the rule.

To handle this issue, perform the operations described in Why Is My Windows ECS Running Slowly?.

  • If the login failure is caused by high CPU usage, perform the following operations to reduce the CPU usage:
    • Stop certain processes that are not used temporarily and try again.
    • Verify that the Windows Update process is not running on the backend.
    • Restart the ECS.
    • Reinstall the ECS OS. Back up important data before the reinstallation.
    • If the ECS OS cannot be reinstalled due to important data, replace the disk attached to the ECS. To do so, back up data on the original disk, detach the disk from the ECS, attach the new disk to the ECS, and copy data to the new disk.

    You can also upgrade the vCPUs and memory by modifying the ECS specifications.

  • If the login fails because the bandwidth exceeds the limit, perform the following operations:

    Check whether the bandwidth exceeds the configured bandwidth size. For details, see How Do I Check Whether the Bandwidth Exceeds the Limit?

    If the bandwidth exceeds the limit, increase the bandwidth. For details, see Changing an EIP Bandwidth.

After you perform the preceding operations, try to remotely log in to the ECS again.

Verifying that the ECS Has an EIP Bound

An ECS can access the Internet only after it is bound with an EIP.

Before logging in to an ECS using RDP or MSTSC, make sure that an EIP has been bound to the ECS. For details, see Assigning an EIP and Binding It to an ECS.

If you are logging in to an ECS through an intranet, for example, using VPN or Direct Connect, you do not need to bind an EIP to the ECS.

Checking Whether the Network Is Functional

Use a local PC in another network or use another hotspot to access the ECS. Check whether the fault occurs on the local network. If so, contact the carrier to resolve this issue.

After you perform the preceding operations, try to remotely log in to the ECS again.

Checking Whether the Firewall Is Correctly Configured

Check whether the firewall is enabled.

  1. Log in to the Windows ECS.
  2. Click the Windows icon in the lower left corner of the desktop and choose Control Panel > System and Security > Windows Firewall.
    Figure 6 Windows Firewall
  3. Choose Check firewall status > Turn Windows Firewall on or off.

    View and set the firewall status.

    Figure 7 Turn off Windows Firewall

Ensure that the remote access port on the local end is allowed on the firewall. The default port is TCP 3389.

If the port configured in the inbound rule of the firewall is different from that configured on the remote server, the remote login will fail. If this occurs, add the port configured on the remote server in the inbound rule of the firewall.

For details, see Adding a Port Exception on a Windows ECS Firewall.

The default port is 3389. If you use another port, add that port in the inbound rule of the firewall.

After you perform the preceding operations, try to remotely log in to the ECS again.

Checking Whether the Remote Access Port Is Correctly Configured

  1. Check whether port 3389 (used by default) on the ECS is accessible.

    Ensure that port 3389 has been added in the inbound rule.

    On the page providing details about the ECS, click the Security Groups tab and view port 3389 in the inbound rule of the security group.

    Figure 8 Checking remote access ports

    For instructions about how to modify a security group rule, see Modifying a Security Group Rule

  2. Check whether the remote access port on the ECS has been changed.
    1. Choose Start > Run, enter cmd, and press Enter. In the CLI, enter regedit to open Registry Editor.
    2. In HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\TerminalServer\WinStations\RDP Tcp\PortNumber, check whether the port is the default port, which is port 3389. If not, change the port to port 3389.

  3. Check whether the number of connections to the ECS is limited.

    Check the internal remote desktop configuration of the ECS.

    1. Choose Start > Run, enter cmd, and press Enter. In the CLI, enter gpedit.msc to open Local Group Policy Editor.
    2. Choose Computer Configuration > Administrative Templates > Windows Components > Remote Desktop Services > Remote Desktop Session Host > Connections. Then, in the Limit number of connections dialog box, check whether the number is limited.

      If Limit number of connections is set to Enabled, a remote connection to the Windows ECS may fail when the number of connections exceeds the limit. In such a case, disable Limit number of connections or set a larger limit for connections.

After you perform the preceding operations, try to remotely log in to the ECS again.

Checking the IP Address Allowlist for SSH Logins (with HSS Enabled)

After HSS is enabled, you can configure an IP address allowlist for SSH logins as required. The IP address allowlist controls SSH access to ECSs, effectively preventing account cracking.

After you configure the allowlist, SSH logins will be allowed only from allowlisted IP addresses.

  1. On the Events page, check whether a local host IP address is intercepted due to brute force cracking.
  2. Check whether the IP address allowlist for SSH logins has been enabled. If it has been enabled, ensure that the IP address of the local host has been added to the IP address allowlist.
    • Before enabling this function, ensure that all IP addresses that need to initiate SSH logins are added to the allowlist. Otherwise, you cannot remotely log in to your ECS through SSH.
    • Exercise caution when adding a local IP address to the allowlist. This will make HSS no longer restrict access from this IP address to your ECSs.

    For more details, see Security Configuration.

Checking the Remote Desktop Protocol on the ECS

Make sure that the remote desktop protocol has been enabled on the ECS (only required for RDP and MSTSC logins).

Log in to the ECS using VNC and enable the remote desktop protocol.

For details, see Login Using MSTSC.

Checking Whether the Access Is Blocked by Antivirus Software

Third-party antivirus software may lead to a failure in accessing the ECS.

If third-party antivirus software is running, check whether the remote connection is blocked by the software. If the remote connection is blocked, add the EIP of the ECS to the allowlist and try to access the ECS again.

You can also disable or uninstall the third-party antivirus software and try to remotely log in to the ECS again.

Checking Whether an Error Occurred During a Remote Login

If an error message is displayed during remote login, check the operation guide based on the error information.

For details, see Remote Login Errors on Windows.

If the error cannot be handled, record the message and the time when the error occurred. Then, click Service Tickets in the upper right corner of the management console, choose Create Service Ticket, and submit a ticket.

If the fault persists after the preceding operations are performed, record your resources and the time when the fault occurred. Then, click Service Tickets in the upper right corner of the management console, choose Create Service Ticket, and submit a ticket.

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