There are two ways to activate Windows:
Using a product key: If you have a product key, you can activate Windows by entering it in the Activation settings. To do this, follow these steps:
Open the Settings app.
Go to Update & Security > Activation.
Under Activate Windows, select Change product key.
Enter your product key and select Next.
Using a digital license: If you don't have a product key, you may have a digital license. A digital license is linked to your Microsoft account, so you can activate Windows by signing in with your Microsoft account. To do this, follow these steps:
Open the Settings app.
Go to Update & Security > Activation.
Under Activate Windows, select Sign in with Microsoft account to activate Windows.
Sign in with your Microsoft account.
If you are having trouble activating Windows, you can try the following:
Make sure that you are connected to the internet.
Try restarting your computer.
Contact Microsoft support for help.
Here are some additional things to keep in mind about Windows activation:
You can only activate Windows one time per computer.
If you change your hardware significantly, you may need to reactivate Windows.
You can purchase a product key from Microsoft or from a third-party retailer.
I hope this helps! Let me know if you have any other questions.