@Apsnei
That message about 0.0MB indidicates that the BIOS thinks your drive has absolutely no free space and the drive basically does not exist. There is nothing we here can do about that. The indication is that your drive has failed and you would need to replace it before you could reinstall Windows.
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.
I am a volunteer and I do not work for, nor represent, HP