My HTC M8 won't reboot and is stuck on the white screen and won't hard reset. What can I do?

[AC Question]

HTC m8 won't reboot,stuck on white screen,won't hard reset won't turn off

Had a system update last night now my phone won't turn off stuck on a white screen. Can't hard reset either. Totally stuck

 

[B. Diddy]

Welcome to Android Central! Force a shutdown by pressing and holding Power for at least 10-15 seconds. Then power on again. If that doesn't help, then try booting into Recovery and wiping the cache partition: https://support.t-mobile.com/docs/DOC-10672