I am not going to discuss how I messed up the system and how it became useless... I have dignity. But I am going to describe how I managed to restore everything and all the googling I made to resolve the issue.
1. Messing with the partition table.
I planed to partition the 320 GiB hardrive this way:
- 80GiB NTFSfor Windows
- the rest of the space for Fedora
As soon as I booted the laptop with the Fedora Live Image, I installed an disk utility called GParted. I deleted all partitions but left the NTFS one and the rest as unallocated.
2. Installing Windows
An important note for this step is that Dell provides an install DVD for Windows. But... Inspiron 11z does not have a DVD drive. I bought an external DVD drive, connected by USB, but I found that the BIOS does not recognize the device as an external USB drive or as an external storage media. WTF!
The only solution in mind was to create a bootable USB media with the install image on it. After several failed programs I tried, I found the one that was successful. It is called Win to Flash.
The link provided has the download link and also explains the procedure. Of course, you have to have the install media for Windows and a 4 GiB USB.
Successfully, my laptop could start the Windows installation media on the USB and it was installed on the intended partition.
3. Installing Fedora.
The rest of the story is very straightforward, because there are a lot of tutorial that explain how to set up a dual boot system. The how-to I followed is located in this link.