King root stuck on 99% and my galaxy S5 keeps rebooting to black screen

[stanhere]

I tried to root my Galaxy S5 using king root on my PC, it took almost 2hrs but now king root is stuck on 99%, not only that but my Galaxy S5 keeps rebooting to a black screen and there's a pop up message that says "process system isn't responding, do you want to close it? " What should I do now? I need some help please.

 

[Rukbat]

About the only thing you can do is remove the battery, disconnect the phone from the PC, replace the battery and hope it starts in normal mode.

If it doesn't, try download mode (Home, Volume Down, Power). If it goes into download mode, you can flash the firmware. See [Samsung] How to flash Stock ROM via ODIN. (The firmware you flash doesn't have any of your files, so I hope you have everything backed up.)

If it doesn't boot into download mode, see if a local repair shop has any ideas.