Using the Activation troubleshooter
You may also check the link below and learn more how to reactivate windows after hardware change
Reactivating Windows 10 after a hardware change
If you're using a product key to activate windows, please follow the steps below to activate windows using command prompt.
To activate your windows using the command prompt
1. Open command prompt with administrator access
2. Type the below commands:
slmgr - upk
3. Restart your computer. Once restarted open command prompt again and type the following command.
slmgr.vbs -ipk XXXXXX-XXXXX-XXXXX-XXXXX-XXXXX >> Replace X with your 25 alpha numeric product key
slmgr.vbs -ato >> This will activate the windows using the product key you've entered on ipk mode.
4. Restart computer and check if windows is activated.