How to Extend Windows Server 2025 RDP 120-Day Grace Period?

Registry Method and Practical PsExec Solution

Narbulut · System Administration Guide

What Is RDP Grace Period and Why Doesn’t slmgr Work?

When you enable the Remote Desktop Services (RDS) role on a Windows Server installation, Microsoft grants you a free 120-day Grace Period. Once this period expires, users can no longer connect to the server via RDP unless you have valid RDS CALs (Client Access Licenses).

Many administrators assume the slmgr /rearm command — used to extend the operating system’s evaluation license — also resets the RDS grace period. This is not the case. slmgr only manages the Windows Server license; the RDS grace period is a completely separate mechanism, reset by deleting the relevant counter key in the Registry.

On Windows Server 2025 Standard or Datacenter, there is no single CMD command that directly resets the RDP grace period. The process requires deleting the relevant time counter key in the Registry. This guide walks you through both the manual Registry method and the practical PsExec alternative that performs the reset with a single command.

Method 1: Manual Registry Reset

You can reset the GracePeriod counter by applying the following 4 steps in order. All operations must be performed with Administrator privileges.

Step 1: Open the Registry Editor

1. On the server, click the Start menu and type regedit in the search bar.
2. Right-click the result and select “Run as administrator”.
3. Use the left-side tree to navigate to the following path:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\RCM\GracePeriod

Step 2: Modify Permissions (Take Ownership)

For security reasons, Windows does not allow you to directly delete keys in this folder. You must first take ownership and enable Full Control:

1. Right-click the GracePeriod folder and select Permissions.
2. In the dialog that opens, click the Advanced button.
3. Click the Change link next to the Owner field at the top.
4. Enter Administrators in the box, click Check Names, then click OK.
5. Check “Replace owner on subcontainers and objects”, then click Apply and OK to close the windows.
6. Right-click the GracePeriod folder again and go to Permissions. Select the Administrators group from the list and check the Full Control permission under the Allow column. Click Apply to save.

Step 3: Delete the L$RTMTIMEBOMB Key

1. Look at the right pane of the GracePeriod folder.
2. Right-click the binary entry whose name starts with L$RTMTIMEBOMB.
3. Select Delete and confirm with Yes.

Step 4: Restart the Server

The reset will not take effect until the server is restarted. Quick restart command from the command line:

shutdown /r /t 0

When the server comes back up, Windows will automatically create a fresh L$RTMTIMEBOMB key, and your legitimate 120-day evaluation period will start from the beginning.

Method 2 (Alternative): One-Line PsExec + PowerShell

If you don’t want to deal with permissions and ownership settings, you can use Microsoft Sysinternals’ PsExec tool to open PowerShell with SYSTEM privileges and delete the key with a single command.

Step 1: Download PsExec

Download PsExec from the official Microsoft Sysinternals page and extract it to any folder on the server (for example, C:\Tools\).

Step 2: Open PowerShell with SYSTEM Privileges

Open Command Prompt (CMD) as Administrator, navigate to the folder containing PsExec, and run the following command:

psexec -s -i powershell.exe

The new PowerShell window that opens runs under the SYSTEM user; there is no need to take ownership or modify permissions.

Step 3: Delete the Key with a Single Command

Remove-ItemProperty -Path 'HKLM:\SYSTEM\CurrentControlSet\Control\Terminal Server\RCM\GracePeriod' -Name 'L$RTMTIMEBOMB_*'

Step 4: Restart the Server

shutdown /r /t 0

Verification: Was the Reset Successful?

After the server restarts, run the following PowerShell command to verify that the grace period has been reset:

Get-WmiObject -Namespace 'root\cimv2\TerminalServices' -Class Win32_TerminalServiceSetting | Select-Object GracePeriodDays

The command output shows the number of days remaining. If the reset was successful, you should see 120 (or a value close to it). If you see a lower value, make sure the server has been restarted, or repeat the steps.

Common Issues and Solutions

Quick Action Summary