Installing a product key in Windows is an essential step to activate your Windows operating system. This process can be efficiently completed using the Command Prompt (CMD), which provides a straightforward method for users who prefer command-line operations or need to automate the activation process.

Step-by-Step Guide to Install a Product Key via CMD

1. Open Command Prompt as Administrator:

   • Press Windows + X and select "Command Prompt (Admin)" or "Windows PowerShell (Admin)" from the menu. This will open the Command Prompt with administrative privileges, which is necessary for executing system-level commands.

2. Check the Current Activation Status:

   • Before installing a new product key, it's useful to check the current activation status. Type the following command and press Enter:

     slmgr /dli

   • This command will display the current licensing information, including the activation status and the partial product key.

3. Install the New Product Key:

   • To install a new product key, use the following command:

     slmgr /ipk <Your-Product-Key>

   • Replace <Your-Product-Key> with your actual 25-character product key. Ensure that you enter the key correctly, including the hyphens.

4. Activate Windows with the Installed Product Key:

   • After installing the product key, activate Windows by running:

     slmgr /ato

   • This command attempts to activate Windows online using the installed product key.

5. Verify Activation:

   • To verify that Windows has been successfully activated, use the command:

     slmgr /xpr

   • This will display a message indicating whether Windows is permanently activated or if there is an expiration date.

Troubleshooting

• Error Messages: If you encounter errors during activation, ensure that your product key is valid and correctly entered. Internet connectivity is also required for online activation.
• Firewall or Network Issues: Sometimes, network settings or firewalls can block activation. Ensure that your network allows access to Microsoft's activation servers.

Conclusion

Installing a product key via Command Prompt is a quick and efficient method for activating Windows. This approach is particularly useful for IT professionals managing multiple systems or setting up automated deployment scripts.