Missing Operating System

I am having this same problem and have given up as of now. I know this post is rather old but thought I would give it a try and see if I could get any help. I have a Dell with Windows 7 and I have gotten as far as Aria on post #9 on this thread where it says 'Failed to transfer logged messages to the event log with status 50'. It is showing I have no drivers installed and when rebooting it still states "Missing Operating System" after press any button to boot from cd drive or whatever. I have no clue what to do. I bought and downloaded the disk for Windows7 X64 cause mine didnt have one off the website and I tried to follow how to do it its just not working. I am not computer savvy. I can navigate through programs but am clueless as far as fixing this thing.
Does the PC have multiple HDDs ?
If so, temporarily disconnect all but the one containing the W7 partition, then try the "startup repair" again.