In most laptop computers, the hard drive contains (among others) a recovery partition from where one can restore the O.S. in case it becomes unusable. This procedure is usually described in the laptop's manual. To recover the system from DVD backup, I think you need to have the recovery software working. If the recovery partition becomes corrupted for any reason, you have to re-install the O.S. from other medium (dvd).
To "erase" the hard drive, you can create a "new partition table". This will overwrite the existing one (perhaps corrupted). What you need to know is the type of partition table you need to select. I think that windows 8 and 8.1 need GPT (GUID partition table) instead of DOS-type (MBR) partition table that was used in older versions like vista, xp etc. If your laptop's BIOS is EFI / UEFI, it is highly probable that you have to select GPT. As for the partitions, it is better to have them made by the windows installer.
Another solution you can try, is to use GParted to delete all existing partitions, and then leave the windows installer to make its partitions at it likes. The first partition is a special hidden partition "Microsoft reserved". The system partition follows.
In any case, within GParted you have to select the operations to do, schedule them in case they are more than one, and then press "APPLY". For general GParted instructions, please refer to the GParted manual (on line).
WARNING: All these solutions will delete the hard drive content, so you have to take backup copy of any important file on this drive before going on.
NOTE: In a few cases, creating a new partition table wasn't sufficient to allow fresh O.S. install. In these cases the solution was to erase the first few MiB of the hard drive content, using the dd command from the command line terminal. If the above mentioned solutions don't work, we can give further instructions.
*** It is highly recommended to backup any important files before doing resize/move operations. ***