I want to change the HDD of my new laptop into a larger HDD, it is Toshiba satellite model C850-b-637. and to change the OS into Windows 7
it dos not boot except from it own original HDD.
I tried to boot it from DVD and from USB flash but I could not do it
Based on your post here it sounds like you have already purchased another HDD, inserted it and cannot install Windows 7 to it? If that is correct then my suggestion would be to jump into your BIOS settings (hit F2 or Del for most computers). Change your boot order, to put DVD and/or USB as a higher priority.