@Gathi
A black screen with flashing cursor indicates that the laptop can not see the boot loader files in order to start the boot process. This probably happened because you are NOW seeing RAID in the BIOS screen, I am reasonably sure your OS was not installed using any RAID mode.
You will have to go into the BIOS settings and disable RAID. You do that by pressing the Esc key repeatedly while rebooting and when the HP Startup Menu appears, press the F10 key to get into Settings.
I am a volunteer and I do not work for, nor represent, HP