C drive wiped accidentally

Hello all, Some of you may have noticed from my previous post s that my wife has accidentally wiped my C drive.
She was attempting a system restore to factory defaults useing the win CD that shipped with the pc.
Trouble is she did this outside of Windows environment i.e.
powered th pc down.
Inserted said disc in the drive.
Powered up pc.
Changed boot order to boot from CD.

Followed on-screen instructions to do the reinstall / factory reset.
The C partition was wiped ,new files loaded.
Then the pc crashed with a message Bootmgr missing press , Ctl Alt Del to race start.
No no joy, pc just loops round this sequence.
I now know it would have been better to attempt. All .this from within the Windows environment by.t hay ho you live and learn.
So I now have an unbootable pc.
I do have a recent Windows back up on my external hd
Would now like to clean install / recover many Windows 7 Home Premium ,if that's possible.
But first,as Windows has apparently wiped me out I would like to know how to interrogate my hard drive
confirm what damage has been done and if it can be recovered.

Thank s all for any help you can give me

Hi the backup I have was .made using the Windows backup tool in the Windows environment.

Thanks ZTRUCKER.
The tutorial would be useful except it assumes that I am able to boot to Windows or a command prompt.
All that happens when I boot th pc is I get a black screen and error message which reads "BOOTMGR is missing Press Ctrl+Alt Del to 'restart"
The only disk I have to recover windows from is a Microsoft external media recovery disk that shipped with the pc.
I think this just allows the pc .to boot an then recovers / repairs the system using files stored on a hidden partition on th hd.
However I think that while incorrectly trying to do a factory reset the recovery disk has wiped c drive ad taken the boot sector with it. So what ever location I try to boot from I am n able to do so.
So I suppose my question should be how do I recover the boot sector / bootleg and then windows from this partition ?

Hello Roland JS,
You must have read my mind.
I was just thinking, I have a program called Partition magic that I used awhile ago to repair a laptop HD / system.
If I remember right the program boots from the disc / optical drive and contains some very impressive tools and utilities..
This at the very least may get me into the HD so I can see ah hidden partitions and then decide if o/s 's salvageable from there.

I will give it a go and post my result.
Now where,s that old dusty box under the bed ?