I was backing up my hard-drive when, zapppowwww, the computer shut off..... when I turned it back on, I get only the manufacturers logo screen (pre-boot) .... eventually it goes to black with the phrase :

"Reboot and Select proper Boot Device or insert Boot Media in selected Boot Device."

Have I lost my Hard drive at the critical moment during backup?? :-( Please help!

Yes it sounds like your C drive has developed problems

Please say it is not so! .... OK, so I guess the next step is to remove it and try it elsewhere? This I will do.

If your hard drive has failed, it is still smart to save it... nearly 90 percent of the time, the data from a hard drive can be recovered even if the drive cannot be made to work right ever again.

Begin by making voluminous notes of what you remember about the install... as the accuracy of your memory will quickly fade. Your files and folders will be in a specific location from which you can drag and drop them with the drive installed as a slave or a non-booting drive. (This is sometimes... not all the time.)

Then when you install a new drive, you can use your notes to good advantage in transferring files.

But remember that defective drive (if it is defective) has only a short life, during which you must recover the data... plan what you are going to do, and how quickly you can do it, while you still have the remains of the drive to use.