OK. It doesn't yet have an MBR and that is the problem.
Boot the machine, go into the BIOS, and set it to boot from your CD/DVD drive - whatever you have. Then open the CD/DVD drive, insert the install disk for your operating system (Windows, Linux, etc), close the drive, and reboot. It should go through the BIOS POST (Power On Self-Test) and then boot from the CD/DVD and read and execute the install program from the CD/DVD you inserted. Follow the instructions and when asked if you want to format the hard drive answer Yes. Then follow through with the rest of the install procedure. It will ask you questions and you answer them according to how you want it set up. When it is complete it will either automatically reboot the system or...