If you are still sitting staring at the stuck screen, press the power button on your computer and keep pressing it until the system shuts off. Wait several seconds before rebooting (starting) the system.
Crashing the computer this way is certainly not something you want to do on a regular basis.
Assuming the computer hardware is OK (disks are "good", for example) and the Windows Operating system is OK (not stuck in the middle of an Update or dead for other reasons), then the controlled "crash" shutdown won't hurt the system and may clear whatever was going on at the time that Windows got stuck.
Next time you boot the computer...
Might best back up your personal data, if you can do so. You know... just in case.
Thank you for participating in the HP Community Forum.
We are a world community of HP enthusiasts dedicated to supporting HP technology.
Click Thumbs Up on a post to say Thank You!
Answered? Click post "Accept as Solution" to help others find it.