Laptop screen black with little blinking dash mark after HP logo upon start up.

[T-53]

Hello, so are on start up the computer starts the fan runs and screen is illuminated with initial go logo screen. Then it goes to a black screen with a little white dash ( - ) blinking on top left corner. And that's where it has stayed and it won't go past that pages. PLEASE HELP WITH DIAGNOSTICS, I WOULD BE FOREVER GRATEFUL,

THOMAS

[WAWood]

@T-53 

You mention using a DV7 but you say you are running Win10.  I thought the DV7s came with Win7, which means if yours did, then you upgraded the laptop to Win10, and this is for a laptop that is what, about 5 years old?

Asking because that flashing cursor means not only that the boot files have been corrupted or are missing, but that critical Windows OS files are also corrupted or missing -- and both of those imply a failed hard drive.

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 -- that will look similar to the image below ...

3) press the Function key for testing the hard drive (usually F2) and let it run.

Please report back the test results.