Machine Account Password Changes - enable or disable? 

Understanding machine account

When a computer is connected to a network (domain), it is given a machine account that represents that computer on the network. This account is used to authenticate the computer allowing it to access network resources and do tasks. Each machine account, also known as a domain member. has its own unique password for each network.

What does Disabling machine account password changes do

Disable machine account password changes controls whether domain-joined machines automatically change their machine account passwords with the domain controller (DC).

By default a machine account is set to disabled, which automatically changes the password every 30 days. This helps to ensure secure communication with the DC and active directory (AD) environments.

The implications of disabling password changes

Enabling disable machine account password changes essentially prevents the computer’s password from being updated automatically. This can have both advantages and disadvantages.

Advantages of disabling 

Disabling machine account password changes can provide increased stability by preventing disruptions caused by password expirations or changes, ensuring consistent communication between machines and the domain.

It also simplifies management, especially in environments with a large number of computers, as managing password changes for each machine can be time-consuming and complex. Disabling this feature reduces the administrative overhead associated with maintaining password updates.

Disadvantages of disabling

Disabling machine account password changes poses a security risk, as a compromised password could be used to gain unauthorized access to network resources.

With password changes disabled, the system can no longer update the password if it becomes compromised, limiting flexibility in responding to security threats. Additionally, if this setting is enabled, the machine will stop changing its password, leading to stale credentials and increased vulnerability over time. This can lead to attackers exploiting static credentials to access domain resources in environments with trust relationships. The lack of password updates could cause authentication or trust issues.

When to disable password updating

Disabling this setting stops the computer’s password from being updated, which can be useful when it is necessary to ensure the computer stays connected to the network and can access resources without interruptions.

Disabling this setting may be necessary when a server needs to remain constantly available or when the computer is part of a critical system where downtime is not an option. Certain security requirements may also dictate the need to disable password changes to maintain consistent access to network resources.

This setting can be particularly useful in specific cases. For instance, in non-persistent VDI environments, where each session begins from a read-only base image, password changes would be lost after the session ends. Similarly, embedded devices without write access to the OS volume may benefit from having this setting enabled.

How to disable machine account password changes

It is possible to disable the machine account password changes on a workstation by setting the DisablePasswordChange registry entry to a value of 1. To do so, follow these steps:

• Start Registry Editor. To do so, select Start, select Run, type regedit in the Open box, and then select OK.
• Locate and then select the following registry subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Netlogon\Parameters
• In the right pane, select the DisablePasswordChange entry.
• On the Edit menu, select Modify.
• In the Value data box, type a value of 1, and then select OK.
• Quit Registry Editor.

In Windows NT version 4.0 and Windows 2000, Windows Server 2003, Windows Server 2008, and Windows Server 2008 R2, can disable the machine account password change by setting the RefusePasswordChange registry entry to a value of 1 on all domain controllers in the domain instead of on all workstations. To do so, follow these steps.

OR

• Start Registry Editor. To do so, select Start, select Run, type regedit in the Open box, and then select OK.
• Locate and then select the following registry subkey:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Netlogon\Parameters

• On the Edit menu, point to New, and then select DWORD Value.
• Type RefusePasswordChange as the registry entry name, and then press ENTER.
• On the Edit menu, select Modify.
• In the Value data box, type a value of 1, and then select OK.
• Quit Registry Editor.
• If RefusePasswordChange registry entry is set to a value of 1, after the workstation or member server first tries to change its machine account password, future attempts to change the password are prevented (by returning a distinct status code).

A Windows NT 4.0-based computer will try to change its machine account password again in seven days, and a Windows 2000-based computer will try again in 30 days. If the RefusePasswordChange registry entry is set to a value of 1, the replication traffic will stop, but not the client traffic. If the DisablePasswordChange registry entry is set to a value of 1, both client and replication traffic will stop.

If automatic machine account password changes is disabled, it can be set up with two (or more) installations of Windows NT or Windows 2000 on the same computer that uses the same machine account. Another possible use for this facility is virtual guests, bringing back older snapshots or disk images but want to avoid having to rejoin the machine to a domain.

Default value 

Disabled. (The domain member can change its computer account password as specified by the recommendation Domain Member: Maximum machine account password age, which by default is every 30 days.)

Possible values 

Enabled

Disabled

Recommended settings 

The recommended state for this setting is: Disabled

Considerations

In dual boot scenarios it is important to avoid using this setting to support dual-boot scenarios with the same machine account. Instead, use different computer names for each installation.

Machine account best practices 

Disabling machine account password changes can be beneficial in certain situations, but it should be approached cautiously and alongside other security measures. Carefully evaluating the systems needs to determine whether the benefits outweigh the risks. If disable password changes, ensure the implementation of strong network security measures, regularly monitor for signs of unauthorized access, and consider alternative approaches, such as group policies or multi-factor authentication.

Similarly, server hardening enhances security and performance by reducing vulnerabilities. Disabling unnecessary services, closing unused ports, and enforcing strong password policies minimize the attack surface, making it harder for attackers to exploit weaknesses. These practices also improve system stability and reduce the risk of unauthorized access, ensuring critical services remain secure and reliable.