How to Change Your Windows Product Key After Install & Activate

If you ever run into a situation where you need to change your product key so you can activate windows, there’s a simple command line technique to do so.  Simply open a command prompt and type in “slmgr.vbs –ipk [product key]


After a few moments, the following message should appear.


When you’re done that, type “slmgr.vbs /ato” to activate windows (see below)


And the following message should appear shortly afterwards if you did everything right.


This works on Windows Vista, Windows 7, and Windows 8.

27 responses to “How to Change Your Windows Product Key After Install & Activate

  1. It doesn’t work for me. I get: “Error: 0xC004F025 Access denied: the requested action requires elevated privileges”. Any ideas?

      1. No, I just went to start, run, “CMD”, and typed in the command line. It is an OLD work computer though…so maybe there is something in the bios that requires admin rights or something, to be able to alter whatever files this is altering?? I don’t know.

  2. i m receiving this error .. kindly help
    ‘slmgr.vbs’ is not recognized as an internal or external command,
    operate program or batch file.

      1. Hi MMMan. I am getting the same message as Raja. I am using Windows 7 Home Premium. I also tried right-click on Computer, Properties and there is no link to the Windows Key. Thanks for your help.

  3. I also get the same error and I am running the cmd as admin. Is it because the product key I have has already expired?

  4. Hi i tried your method and every thing went well till the last window.
    It shows
    Activating Windows(R) 7, Professional edition
    Error: 0xC004c008 The activation server determined that the specified product key could not be used.

    1. Sounds to me like your product key could’ve been activated too many times already. Typically if you call the Microsoft software activations department, they can help clear that up for you.

  5. Thanks. Spent three hours on this. After going into start -> and -> cmd.exe and then typing the ‘slmgr.vbs’ line with the new product key, DO NOT push the enter key, but instead push Ctrl+Shift + Enter. This is running a command as Adminstrator and was what I was doing wrong for 3 hours.

  6. I followed th same step to change my windows key and this dialogue box is apprearing

    On a computer running Microsoft Windows non-core edition, run ‘slui.exe 0*2a0*C004F015
    Error: 0*C004F015

    Sir plz help
    What to do now?

  7. It is not worked on already activated windows 7.
    I need to change key after activation.

  8. hi, i m run in admin. i got the error“Error: 0xC004F025 Access denied: the requested action requires elevated privileges”.

  9. it says: Error: product activation failed…
    after entering product key in cmd….

  10. My laptop’s previous owner upgraded it to windows 8. If I change it to the product key on the back of the laptop, will there be a problem?

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