windows 8 laptop. how can I tell if my harddrive gone bad

my asus windows 8 laptop will not boot up. it says preparing to repair and sits there. I have no install disks for windows 8. I can not boot up the laptop. SO how can I tell if my hard drive is problem or windows? thanks

Few solutions here.
You can ask Asus for a restoration disk.
Make a Windows 8 Boot disk on DVD or USB (one another computer) and initialize repair from there. An W8 ISO file has to be downloaded first.
Make a Linux live boot disk or USB and check HDD itself.

In addition to what Mike suggested above. You can also download Macrium Rescue ISO: Macrium WinPE .iso - OneDrive created by WHS. Use Rufus - Create bootable USB to create a bootable USB. Boot up the Laptop, you'll see a screen shot shown below. Click on Fix Windows Boot Problems: