There is the possibility of one of two things:
1. Virus/Malware called TDSS Rootkit
2. Hard drive not being recognized by operating system or BIOS.
Here's what to do first:
When the computer boots, enter Setup mode by pressing DEL or F12 or whatever system hotkey is available.
Once there, look for hard drive settings. You should see information about your hard drive there. If you see the word none listed, the hard drive is not recognized by the BIOS. If you see a brand name or model number listed, it is being recognized by the BIOS but not by the operating system.
NOW, if the hard drive is being recognized by the BIOS, then please do the following:
If you are not sure how to burn an image, please read
How to write a CD/DVD image or ISO. If you need a FREE utility to burn the ISO image, download and use
ImgBurn.
Let me know how it goes.