Getting help with activation errors

Here are some of the most common activation errors in Windows and a few things you can try to fix the problems that are causing them. For additional help with the activation process, contact support.

Activation error What it means and how to fix it
Activation error

Unable to find detailed error description. (Error code: 0xC004C4AA)


Unable to activate Windows 8.1 Pro with Media Center or Windows 8 Pro with Media Center

What it means and how to fix it

You might see this error after you've used Add features to Windows 8.1 or Add features to Windows 8 to upgrade your current edition of Windows to Windows 8.1 Pro with Media Center or Windows 8 Pro with Media Center. You can only activate different editions of Windows on PCs that had Windows pre-installed, or Windows purchased on the Windows website or at a retail store. To fix the problem, you need to install Windows with the product key provided to you in a purchase confirmation email or with the DVD. If you think that you've received this message in error, contact a Microsoft Customer Support representative.

Activation error

Unable to find a detailed error description. (Error code: 0xC004C400)


Unable to activate Windows 8.1 Pro with Media Center or Windows 8 Pro with Media Center

What it means and how to fix it

You might see this error after adding the Windows Media Center Pack and trying to enter your new product key. To fix the problem, you can activate Windows by phone.


  1. Swipe in from the right edge of the screen, then tap Search.
    (If you're using a mouse, point to the bottom-right corner of the screen, move the mouse pointer up, then click Search.)

  2. Enter SLUI 04 in the search box, then tap or click SLUI 04.

  3. Follow the instructions on the screen.

Activation error

Genuine Validation detected tampered Windows binaries. (Error code: 0xC004C4AE)

What it means and how to fix it

You might see this error if you used a third-party application to add a display language that isn't currently supported by Windows. To fix the problem, you can restore your PC to an earlier point in time to undo the changes that were made to Windows. For more information, see How to refresh, reset or restore your PC.

Activation error

The Software Licensing Service determined that the specified product key can only be used for upgrading, not for clean installations. (Error code: 0xC004F061)

What it means and how to fix it

You might see this error if you're using a product key to upgrade to Windows 8.1 or Windows 8, but a previous version of Windows wasn't installed on your PC. To upgrade, you need to have Windows 8, Windows 7, Windows Vista or Windows XP already on your PC. For more information, see Why can't I activate Windows?

Activation error

A networking problem has occurred while activating your copy of Windows. (Error code: 0xC004FC03)

What it means and how to fix it

You might see this error if your firewall settings are preventing Windows from completing the activation process online. To fix the problem, you can activate Windows by phone instead.


  1. Swipe in from the right edge of the screen, then tap Search.
    (If you're using a mouse, point to the bottom-right corner of the screen, move the mouse pointer up, then click Search.)

  2. Enter SLUI 04 in the search box, then tap or click SLUI 04.

  3. Follow the instructions on the screen.

Activation error

The activation server reported that the product key has exceeded its unlock limit. (Error code: 0xC004C008)

What it means and how to fix it

You might see this error if the product key has already been used on another PC, or it's being used on more PCs than the Microsoft Software Licence Terms allow. To fix the problem, you'll need to buy a product key for each one of your PCs to activate Windows on them.

Activation error

This product key didn't work. (Error code: 0xC004C003)

What it means and how to fix it

If you've recently used Add features to Windows 8 to get an edition of Windows with more features, you might see this error if you immediately updated to Windows 8.1 in the Windows Store. To fix this problem, you'll need to contact a Microsoft Customer Support representative.


You might also see this error if you're using an invalid product key. You'll need to buy a new product key, or if you bought a PC with Windows pre-installed, contact the PC manufacturer for the original key.

Activation error

The activation server reported that the Multiple Activation Key has exceeded its limit. (Error code: 0xC004C020)

What it means and how to fix it

This error occurs when a Volume Licence (a licence that has been bought from Microsoft by a business to install Windows on multiple PCs) has been used on more PCs than the Microsoft Software Licence Terms allow. To fix the problem, you might need to use a different product key to activate your PC. Contact your system admin for more information.

Activation error

DNS name does not exist. (Error code: 0x8007232B)


The file name, directory name or volume label syntax is incorrect. (Error code: 0x8007007B)

What it means and how to fix it

You might see this error if you're trying to activate your work PC but aren't connected to your workplace's network. If you're connected to your work network and still see this error, you might need to change your network settings. Contact your system admin for more information.


If you don't have a system administrator, you might need to enter your product key again. Follow these steps:


  1. Swipe in from the right edge of the screen, then tap Search.
    (If you're using a mouse, point to the bottom-right corner of the screen, move the mouse pointer up, then click Search.)

  2. Do one of the following:

    • In Windows 8.1, enter product key in the search box, then tap or click Change your Windows product key. Under Windows, tap or click Change product key, then enter your 25-character product key.

    • In Windows 8, enter SLUI 03 in the search box, then tap or click SLUI 03. Enter your 25-digit product key, then tap or click Activate.

    Administrator permission required You might be asked for an admin password or to confirm your choice.

Activation error

A security error has occurred. (Error code: 0x80072F8F)

What it means and how to fix it

You might see this error if the PC's date and time are incorrect or Windows is having trouble connecting to the online activation service and can't verify your product key.


To verify your PC's date and time, follow these steps:

  1. Swipe in from the right edge of the screen, then tap Search.
    (If you're using a mouse, point to the bottom-right corner of the screen, move the mouse pointer up, then click Search.)

  2. Enter date and time in the search box, then do one of the following:

    • In Windows 8.1, tap or click Date and time settings.

    • In Windows 8, tap or click Settings, then tap or click Date and Time.

To check your Internet connection, follow these steps:

  1. Swipe in from the right edge of the screen, then tap Search.
    (If you're using a mouse, point to the bottom-right corner of the screen, move the mouse pointer up, then click Search.)

  2. Enter network troubleshooter in the search box, then do one of the following:

    • In Windows 8.1, tap or click Identify and repair network problems.

    • In Windows 8, tap or click Settings, then tap or click Identify and repair network problems.

Activation error

The Software Licensing Service reported that the licence evaluation failed. (Error code: 0xC004E003)

What it means and how to fix it

You might see this error after installing third-party software that has changed system files. Windows activation needs certain system files to complete activation. You can try to restore your PC's system files back to an earlier point in time. This will remove any software that you've installed after that point in time without affecting your personal files. For more information, see How to refresh, reset or restore your PC.

Activation error

Unspecified error. (Error code: 0x80004005)

What it means and how to fix it

If you see this error, try activating again. If that doesn't work, you might need to restore, refresh or reset your PC. For more information, see How to refresh, reset or restore your PC.

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