Remove Users from Local Administrators Group using Group Policy

In this guide, I’ll show you how to remove users from the local administrator group using group policy. 

I’ll also show you how to add users or groups into the local administrator group. 

By using group policy you can gain control over admin rights and ensure no unwanted account is added into the local administrator group. 

What you will learn in this guide: 

Why Local Administrator Rights is a Huge Security Risk

You do not want your users to log into computers and perform daily work with administrator rights. Exploiting administrator rights is a primary method attackers use to spread and gain control of systems inside and organization. 

Scenario 1: A user is logged in to their computer with administrator rights, this person is fooled into opening an email that contains a malicious attachment. This attachment contains executable code and is executed on the computer. Because the user is logged in with administrator rights this malicious code has full rights to the computer, it could install a keylogger, sniffer, run ransomware and encrypt all the files, install remote control software, and so on. Not good. 

Scenario 2: Someone..maybe a helpdesk tech created a local user on multiple computers with the same password and added it to the local administrator group. If an attacker cracked this password the attacker then has administrator access to all the machines that this account is created on. The attacker could then move laterally from system to system dropping malicious files, stealing data, and so on. 

Both scenarios can be mitigated by getting control of your local admin groups. Now… Let’s move on to the tutorial. 

How to Remove users From The local admin group with group policy

First, let’s check a computer and see what accounts are in the local administrator group. This can easily be done by using the following PowerShell command.

Get-LocalGroupMember administrators

You can see in the screenshot there are several local and domain users in the administrator group. 

This is bad. 

Using group policy I can not only remove these accounts but I can control what user accounts or groups are members of this group. If someone tried to manually add a user to this group the group policy would override it. 

I like to put all computers in an organizational unit, this makes it easy to apply group policies to computer accounts. 

Step 1. Right-click the organizational unit where you want to the GPO applied and select  “Create a GPO in this domain, and link it here” 

Step 2. Name the GPO and click OK

Now you need to edit the GPO. 

Step 3. Right-click the GPO and click edit

Step 4. Browse to the following GPO settings

Computer Configuration -> Preferences -> Control Panel Settings -> Local users and Groups

Now right-click in the right side window and select new -> Local Group

Settings: 

Action: Update
Group name: Administrators (built-in)

Delete all member users: Yes
Delete all member groups: Yes

Members: Click add and select the members you want to be added to the local administrator group. You probably want to keep the local administrator account and domain admins group as local admins… but that is totally up to you. 

Screenshot of my settings

The above settings will both delete all users and groups and then add the users specified in the members box. This will clean up all unwanted accounts and add only the accounts you want in the local administrator group. 

Test the Group Policy

Now that the GPO is created and linked to an organizational unit lets test it. 

On PC1 I will run the following command to force a group policy update.

gpupdate /force

Once the command completes I’ll check the group membership again.

Awesome! 

You can see from the screenshot that the unwanted accounts have been removed from the administrator group. The GPO removed the robert.allen account, admin2, and the fig account from the group. It then added the domain admins group, the IT_Wrk_Admin group, and the local administrator account. 

Any computer you apply this policy to will get these exact settings. If you choose to delete all member user and group accounts it will indeed remove those accounts from the local administrators group. I recommend you test this before rolling it out into production. 

Exclude Computers from the GPO Policy

If you need to exclude a computer from this policy follow these steps: 

Tip: There are many poorly coded programs out there that don’t run without giving users admin rights. If you can avoid these programs please do so. It’s ridiculous that there are still companies selling software that cannot run with admin rights…again try to avoid these programs. If you can’t then look into privilege escalation programs like BeyondTrust and PolicyPak. These programs allow you to configure programs to run without giving the user administrator rights. 

Step 1. Create a new active directory group. Name it whatever you want. 

Step 2. Add the computer account that you want to exclude into this group.

Step 3. In the group policy management console, select the GPO you created and select the delegation tab. 

Now click the advanced tab

Click add and select the group you just created.  

Now make sure this group has only these permissions:

Read: Allow
Apply group policy: Deny

This will deny any member of this group from applying the GPO. This is a very simple approach to excluding computers from applying this GPO. It also makes it easy to manage, if you want to know who is excluded from a GPO you can just check the members of the AD group. 

Now, I’ll verify the computer is excluded by using the gpresult command. 

To see all the GPOs applied to a computer and user type this command.

gpresult /r

You will need to be an administrator on the computer to get the computer results.

You can see the GPO “GPO Computer – Local Admin Group members” is applied to this computer. I will reboot the computer and run the command again. Once I reboot I should no longer see that GPO being applied to this computer because it’s being denied from applying. 

I will run gpresult /r again 

You can see the GPO is no longer applied to this computer. 

Tip: You should first do an audit of user rights and understand why they have admin rights. You don’t want to enable this policy on all computers without first testing and understanding its impact. Unfortunately, there are programs that still need elevated rights, and applying this policy could break and prevent programs from running. 

When I rolled this policy out I first ran a report of all users that had admin rights. I then reviewed the rights with staff to better understand why the users permissions, most of it was due to old programs that needed elevated rights. This was then discussed by upper management and approved before moving forward. Test, Test, and Test before rolling this out to production systems.

If you have any questions post them in the comment section below. 

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18 thoughts on “Remove Users from Local Administrators Group using Group Policy”

  1. Great information but I have a question. When you delete all member users and then add the local administrator account back in, what is the password for the administrator? Does it remain the same that it was prior to being deleted by putting a check in the box to delete all members?

    Thanks!

    Reply
    • The password is the same. It doesn’t delete any accounts on the local computer it just removes them from the administrator group.

      Reply
      • What if the account didn’t exist? Say for example all new computers you set up an account named Owner that you want as an admin on the local machine as well, but maybe that account didn’t exist on some of your older machines. If it didn’t exist on the computer before, does it create that Owner account or just ignore it? If it creates it, what does it use as the password?

        Reply
    • Hi Robert i have a question i have set this policie so now each local computer has an local account without admin right. A few dans later I would like to set admin right to the local account for 2 workstation. Is it possible to do it ?
      Thanks you by advance for your help

      Reply
  2. I dont know why, but instead of add admin group to group Administrators (built in) it create another group with that name and add admin groups here. I cant find why. GPO is applied. But doesnt work. Any idea?

    Reply
  3. Great article, just a few comments:

    We use this for years now and in our group policies we removed the local admin from the administrators group too. That said, we found that still the local administrator is a member of the administrators group on every system!

    Individual administrators can be added by using variables in the GPO and matching groups in AD. So for example %DomainName%\%computername%_admins in the GPO. Only thing you should keep in mind is that this could be abused of course and so assign to the lowest OU possible.

    Finally you can stack up several policies from highest to lowest OU. For example the first GPO on domain level removes all members, the second on highest OU level adds the DomainName\Workstation_admins, the third adds the DomainName\US_Sales_admins on the US Sales OU and on the Washington Sales OU the fourth GPO adds the mentioned %DomainName%\%computername%_admins to the local administrators group then on all computers for those a corresponding AD group exists.

    Reply
    • Thanks for sharing. I’ve also been using something similar for years now, it really helps to keep control of the local admin group. Prior to this, I would run reports on who is in the local admin group and then complain to the helpdesk to stop adding users as local admins. This put an end to that nightmware.

      Reply
  4. Hi Robert
    I removed some days ago all admin rights on all local acounts(I checked delete all member users and I delete all members group). For the moment only specific AD users member of a group named LocalAdmin are Admins.

    I realized that it could be a good idea to have a local user on each computer with admin rights : for example in case of link broken with the domainServer (ex: workstation ejected from the domain for any reasons…)
    So I would like to update my GPO by adding a localuser for each workstation. Do you think it is still possible?
    If my user is named localPerson on all workstation, I just have to add LocalAccount into members area?
    thank you by advance for your help

    Reply
    • To add a local user just put the username without the domain in the GPO, like this.

      user1
      adpro\workstation admins
      adpro\helpdesk

      You will have to create the local account first, this does not create it.

      Reply
  5. What did you use to run a report that would show all users with local admin rights? I have been looking to do that but have not found a reliable method.

    Thank you!

    Reply

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