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The error code 0xc004c008 usually appears when you install the Windows 8.1 or Windows 10 product a number of times. Because the Windows 10 or Windows 8.1 license can only be installed on one device, and of course, if your device fails and you buy a new device or simply modify a hardware component, you may need a new product activation code.
Basically, when you reinstall the Windows operating system you previously purchased and installed on another computer, an error code appears with a message indicating that the activation server has determined that the specific key could not be used to activate. This happens because the key has already been used on this or another computer to install operating systems. There are a few simple solutions to this problem, and most of them should be easy to implement on their own.
How to Fix Windows 10 Activation Error Code 0xC004C008:
Press and hold the Windows key and the R key to open the Run window. You can also open Windows from the Start menu of the Windows 8.1 or Windows 10 system.
Type the command: “SLUI 4” in the Run window.
Then press the “Enter” key on the keyboard.
As soon as you press the Enter key, a “Phone Activation” window appears in front of you.
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Select the country from which you registered in the window.
After selecting the country, call the activation number.
You will be prompted to enter your “Installation ID”.
Note: Enter the installation ID on your phone.
After entering the installation ID, you will be asked how many copies of Windows have been installed with this license, and you will need to select “1”. If you choose another option, it will not work.
Note: The option “1” you have selected means that you have only used it once.
Activate Windows manually
1. click on Start and enter the name: slui.exe 4 in the search field.
2. press ENTER on your keyboard.
3. select your country.
4. Select the Phone Activation option and hold down the button for a real person.
Perform Windows activation Troubleshooter
- Press the Windows + I button to open the settings.
- Select Update and Security and open the Activation tab.
- Click on the Troubleshooting button.
NOTE: To perform the troubleshooting, you must log in as an administrator.
Use of an extended Command Prompt
- Click on Win + R, type Slui 4 and press Enter.
- Then the Win + S button to open the settings.
- Select Update and Security, then click Activation.
- If your PC is not activated, you will receive the Activate option by phone.
- Then launch the Product Activation Wizard.
- Open the Charms menu and click Settings.
- Then go to Edit PC Settings and click Enable Windows.
- Click on one of the options, for example, Activate, Activate by Phone or Contact Customer Service for help.
- Follow the instructions on the screen and activate Windows from your phone.
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CCNA, Web Developer, PC Troubleshooter
I am a computer enthusiast and a practicing IT Professional. I have years of experience behind me in computer programming, hardware troubleshooting and repair. I specialise in Web Development and Database Design. I also have a CCNA certification for Network Design and Troubleshooting.