|The format of these command is very important. They won't work if you get them wrong.|
It is NOT Scf/scan now
It is sfc /scannow
(only one space, after sfc).
Whatever, you can't use any of these commands if you can't get to Windows.
I would be inclined to boot using a Live Linux CD, which doesn't use Windows or the HD at all. You create it on another computer and use the "Burn Image feature". Put the CD ahead of the HD in BIOS on the faulty computer, then power-up with the CD in the drive.
If Linux boots up and you can see the HD, then it proves that Windows software is at fault. Right now your issue could be most anything, including hardware.
Always pop back and let us know the outcome - thanks