The activation clock gives testers and end users a 30-day grace period during which Windows® activation is not required.

Caution:
  • To make sure the grace period does not expire between the period when you prepare the Windows image and when the end user receives the computer, you must reset the activation clock. This is known as rearming the activation clock. If the grace period has expired, Windows prompts the user for the license key as soon as the user boots up the computer.

  • To automatically activate Windows by using a product key, use the Microsoft-Windows-Shell-Setup\ProductKey setting. For more information about activating Windows, see Work with Product Keys and Activation.

Rearm the Activation Clock

By default, each time you generalize the computer you rearm the Windows activation clock. When a computer with a rearmed Windows image boots, the grace period begins and the end user has 30 days to activate that installation of Windows. For more information about generalizing the computer, see Prepare to Capture an Image for Deployment (Generalize).

  • If you are a Key Management Service (KMS) client, you can generalize the image to rearm the activation clock an unlimited number of times. KMS requires the end user to be able to connect to a functional KMS host on the network, with an appropriate key installed to activate the computer. For more information about KMS, see the Volume Activation Planning Guide.

  • If you do not use KMS, you can generalize the image to rearm the activation clock. However, you can rearm the clock only a limited number of times, determined by the Windows edition. After you reach this limit, you can still generalize the image, but the activation clock is not rearmed.

Delay Rearming the Activation Clock

If you do not use KMS and need to generalize the image more than a few times, you can delay rearming the clock by skipping the Windows Software Licensing Rearm program:

  1. Set the Microsoft-Windows-Security-SPP\SkipRearm unattended setting value to 1. Then, generalize the image as many times as necessary. Windows Setup does not rearm the image.

  2. To prepare the image for deployment, set the Microsoft-Windows-Security-SPP\SkipRearm value back to 0, and then generalize the computer again. This rearms the activation clock and prepares the computer for shipping to the end user. All activation-related licensing and registry data is removed or reset, and any grace-period timers are reset.

Detect How Many Times You Can Rearm the Activation Clock

To see how many times you can rearm the Windows activation clock, open a command prompt and use the slmgr /dlv command. A Windows Script Host window appears with the current state of the Windows Activation clock.

See Also