It would be my tip to all new users but I can tell you it rarely happens and by the time we see them here looking for help it is often too late.
My back-up attempt always appear to be over 75 gigabytes. Its too much to do or to keep doing.

Its a mass of stuff I have shared between 3 computers. 10 years of files. Some stuff is copied and some stuff is lost.
The Tosh vista laptop I am using has two hard drives. One for back-ups (I think); and I have never had any real problems with this one.
The Windows 7 laptop only failed the first time after a couple of months and then repeatedlly froze dozens of times. I did call Toshiba (Japan) helpline; but it takes a week to get anyone English speaking to call you back. By which time the Computer began working normally; sometimes.
But it kept going wrong. I thought it might be the heat (its around 30 degrees here and can be 60-75% humidity in the building I write/type in).
Anyway I ran the STARTUP REPAIR Disk repair for 24 hours and nuthin. I then took it out and put the hard drive an a USB3 removable hard drive and did a SCAN-DISC from this Vista laptop.
The program said there were no errors after an hour of scanning it. I have a screenshot of the record jpg.
I put the hard drive back into the Win 7 laptop and again its black screen and trash.
Still waiting to see if the repair box will come up again.
Computers suck the life out of my will to live sometimes. No surprise Microsoft had its first year posting a loss for the company this year.
ALSO;
the repair software you all mention (here and elsewhere). I can never find out the simple information on wether I can install it on my x32 Vista laptop and plug the hard-drive of the Windows 7 Ultimate x64 into the external USB drive and run the repair program that way.
Does anyone know? Or does a 32-bit program not function on a 64 bit drive with a different operating system?

?
ALSO;
I do have a spare hard-drive with Win vista on it; and it did start up perfectly in the Win 7 laptop. I made it 6-months back when the hard-drive got replaced again. The laptop is not at fault. The only thing is with the Vista 32 bit program running in the 3D laptop it will not let me connect to the internet. Pressing the connect to the internet button causes the Music program to start instead.
The hard-drive is only 60-Gig which is why I can't use it for back-ups (which are over 75-gig). I have a lot of Blu-ray film family vids; pics/work docs/ tons of stuff.
Anyway; back to slashing my... dinnertime.