Sorry for butting in here, but I see this a lot at work.
If you can't get to the boot screen by pressing F12 at boot, then IME it's most likely a hard drive problem.
And having the backup show 0 bytes is also a symptom of a hard drive problem (although it can be other things).
The test we do at work is to remove the hard drive and then see if the F12 key combo works.
Be sure to remove the power and battery before opening the case - and to ground yourself before handling the hard drive.
Then connect the power (it's OK to leave the battery out) and see if F12 gets you to the boot selection menu.
If that doesn't work, then the next thing to check is the RAM,
But that's a bit more finicky - as you have only 2 sticks and 2 slots
In that case, you try one stick in each of the slots and then the other stick in each of the 2 slots.
The point here is being sure that you remove power and ground yourself before handling the RAM each and every time.
You're again looking for the ability to get to the boot selection menu using the F12 key
In the event that it's a bad hard drive you'll have to contact Toshiba for a set of recovery disks. Last I knew they were around $45 (US), but that's a lot cheaper than a new copy of Windows.
Here's a link for that (last updated in 2012): http://www.carrona.org/recdisc.html
This is the exact issue I'm facing and I was hoping that it wasn't hardware. I'm afraid it might be though. I'll try to get into my BIOS and see if I can update it. In the meantime, I did try the RAM stick removal and switch, but the computer was plugged in the whole time I was doing that. I'll unplug it and try that again. Any other recommendations?