I can't boot into my laptop. It only shows small white line at top left corner

[AshfaqueMohamme]

When I press power button, it only shows black screen with white small line at top left corner. I can't boot into bios too. No option to boot into windows. Tried everything. Please help. I am helpless.

[WAWood]

@AshfaqueMohamme 

That blinking line, known as a "cursor" is displayed when Windows has been corrupted on the drive so badly that the OS can't even read the boot loader -- so basically, nothing happens.

This issue is often due to a failing drive. So, let's check that first, because if it is failing, it would need to be replaced and there is no point then in doing anything else until we confirm that.

If your PC is new enough to support UEFI, you can use these steps to test the hard drive: http://support.hp.com/us-en/document/c00439024

If not, to check the drive you have to follow these steps:
1) Press Esc key repeatedly, several times a second, while rebooting the laptop. Do NOT hold the key down, just press it over and over.
2) Eventually, you will see an HP Startup Menu
3) Press the Function key for testing the hard drive (usually F2) and let it run.
If the drive checks out OK, then report that and I can provide you options for reinstalling Windows on your PC.