After installing Windows 7 on a non-OEM machine without a product key for activation, Windows 7 operating system will run in Initial Grace Period license status, which lasts 30 days as evaluation or trial period. When the initial 30-day activation-free grace period going to expire, users can rearm Windows 7 for additional 30 more days of activation grace period, for up to 3 times, effectively allowing Windows 7 to run legally for 120 days without a legit or genuine product key to activate the system.

When a user uses up all three rearms available and remaining rearm count countdown to 0 (zero) , the only option left is to enter a legit and genuine product key to activate Windows 7, or left the Windows 7 goes into non-genuine status, where user will face several annoyances such as black desktop background, repetitive notification messages to inform users that the Windows is illegal or counterfeited, and reminder to activate and witch to genuine Windows 7 on desktop or upon logon.

Through a WPA vulnerability that Microsoft introduced in Windows 7, it’s possible to reset the remaining rearm count back to 4, which is the default number of times the rearm is permitted in out-of-the-box Windows 7. The ability to reset the rearm count for as many times as possible (infinity times until patched by Microsoft) allows users to run Windows 7 forever, without the need of activation nor modding the BIOS, and without applying any activation cracks.

The said WPA vulnerability is related to a WPA registry key which contains Last Rearm Time information in Windows 7. When the WPA registry key is deleted, the whole licensing status of Windows 7 is re-initiated to the Initial Grace Period (more on Windows 7 and Visa license status), as if Windows 7 is just installed in OOBE (out of the box experience). The deletion of the WPA registry key is achievable with the following command:

reg load HKLM\MY_SYSTEM “%~dp0Windows\System32\config\system”
reg delete HKLM\MY_SYSTEM\WPA /f
reg unload HKLM\MY_SYSTEM

With the importance of WPA registry key, it’s understandable the Microsoft locks the key and all its sub-keys from been changed, modified, removed or deleted in normal user session. So users have to run the command manually from WinRE (Windows Recovery Environment) or WinPE (Windows Preinstallation Environment).

Resetting the remaining rearm back back to default 4 is better than Windows 7 activation cracks (other than BIOS mod OEM activation of course) such as RemoveWAT and Chew-WGA as there is no crack been installed, and Windows 7 will forever run in Initial Grace Period license status, which is allowed by Microsoft and deemed genuine by WGA validation. No product key and no activation is required. For users who want to reset the rearm count in Windows 7 to run Windows 7 forever, the guide to reset rearm count as detailed on MDL forums is shown below. The best advantage of the guide is that there is no messing or changing of important system files, as demanded by some Windows 7 activation crack programs, such as Windows 7 Loader eXtreme Edition by napalum which not only modify winload.exe, but also ntoskrnl.exe and BCD store in order to achieve the reset.

There is two disadvantages to hack to run Windows 7 by rearming. Firstly, users have to rearm Windows 7 every 30 days. Secondly, users have to reboot the computer into WinRE or WinPE to perform a simple command every 120 days (4 rearms allowing a maximum of 120 days free usage, with each rearm brings 30 days activation grace period).

  1. Create a batch script file with the following commands:

    reg load HKLM\MY_SYSTEM "%~dp0Windows\System32\config\system"
    reg delete HKLM\MY_SYSTEM\WPA /f
    reg unload HKLM\MY_SYSTEM

    Save the file as delwpa.bat on drive C:\ at the root folder level. For example, C:\delwpa.bat. Note that some users may require to run the text editor such as Notepad as administrator to save to C:\ root directory.

  2. On the day where days remaining to activate Windows 7 is about to approach 0, restart the computer.
  3. Press F8 on boot or right after the BIOS screen to get to the “Advanced Boot Options”.
  4. Select Repair Your Computer.
  5. Select your keyboard input method, and click Next.
  6. Enter user name and password login credentials, and click OK.
  7. In the “System Recovery Options”, open Command Prompt.
  8. Type C: to go to the main drive, and the execute the delwpa.bat file by type its name:


    Note: On some computers such as virtual machine or computer with recovery partition, the main drive may appear as D:

  9. The console should display messages saying that the commands were executed successfully. Close the console window and reboot the machine.
  10. After system startup, sign into Windows. System will display message such as “This product is not genuine”. Just ignore it.
  11. Run Command Prompt as Administrador, and execute the following command to re-insert the default Windows 7 product key into the system. These product keys, which is on every unactivated Windows 7 right after installed, allow Windows 7 to be used for 30 days without activating it with further 3 rearms available. Note that the command should be run according to the installed Windows 7 edition:

    Ultimate: slmgr /ipk D4F6K-*****-*****-*****-*****

    Professional: slmgr /ipk HYF8J-*****-*****-*****-*****

    Home Premium: slmgr /ipk RHPQ2-*****-*****-*****-*****

    Home Basic: slmgr /ipk YGFVB-*****-*****-*****-*****

    Starter: slmgr /ipk 7Q28W-*****-*****-*****-*****

    Product keys removed due to Demand for Immediate Take Down – Notice of Infringing Activity – MS Ref. 309109 from

  12. Reboot the computer.
  13. Login, and the Windows 7 OS is now in initial grace period of 30 days. To check the activation status, open an elevated command prompt window as administrator, and run the following command:

    slmgr /dlv

    The dialog box with the following details should appear:

    License Status: Initial Grace Period
    Time remaining: 30 days
    Remaining windows rearm count: 3

  14. In order to rearm the Windows 7 system for additional 30 days activation grace period, open an elevated command prompt window as administrator, and run the following command:

    slmgr /rearm

Most of the batch file creation, installation and rearm process is now automated with unlimited rearm count reset utilities, although users still have to manually run the reset script batch file in WinRE or WinPE.

Tip: As an alternative, it’s possible boot from a Windows 7 Repair Disc or a Windows 7 installation disc to go to WinPE environment, where user no need to enter login credentials. Pressing F8 will bring user to WinRE console.

Disclaimer: This article is for information and education purpose only.