Solved Boot Mischief: What causes "Missing Operating System" msg?

[Chaim613]

Hi,
I'm a novice, but puzzled, I love getting to the bottom of things. Here's one I'm working on, but I'm at an impasse (I'm going to run out of time, school starts next week):
After a re-install of Win7 Pro on Lenovos Desktop with WD5000AAKS drive, I get "Missing Operating System" when the machine is rebooted with no disk in the drive.
Machine boots if I put GRMCPRXFRER_EN_DVD (the Win7 Install Disk) in the drive before powering up or Restart.
I've re-installed more than a half dozen times with same outcome.
I've tried re-installing from 2 sources, the above mentioned Win7 Install Disk, and a Restore Disk from Lenovos, both gave same outcome. Each source was tried several times, same outcome each time.
I've tried switching the HDD mode between RAID and ACHP(?), same outcome each mode.
I've tried re-installing the Western Digital HDD driver, same outcome.
My disk partition is:

 

[Gator]

Hi Chaim, this error can generally only mean two things. Your hardware failure or your MBR is damaged.

Try to follow the steps here:
Missing operating system: Windows 7 (2014 Update)

 

[gregrocker]

Please stop creating new threads for this. I was helping you in another thread which was abandoned without reply to steps I gave you.

Work through these steps for Overcoming Windows 7 Installation Failures - Windows 7 Help Forums . Do not skip any steps including trying new installation media ISO burned to stick or written to disk with tool provided.

If it still fails test your hard drive and RAM from http://www.sevenforums.com/tutorials/220165-troubleshooting-steps-windows-7-a.html