I bet you're confused ! I couldn't get a minute for myself at the time I was writing this ...
Let me rephrase the whole thing.
I bought a notebook from Medion last week, P6815 to be sharp. W8 was preinstalled when I got it. Of course I knew it, but I thought that getting rid of it for Windows 7 was an easy task ... except it wasn't at all since all the changements of W8 starting from the UEFI BIOS. After a friend of mine fixed it for me we had issues seeing the partitions, no HDD no nothing. Finally with the help of Medion's helpdesk my friend found a solution (while Medion's staff told us theyll get back to us in a few days to help us more as they couldn't find any way out of it, yet they gave a my friend a clue to get over it).
In the end, we installed Windows 7 x64 ultimate on the internal 32Gb SSD while the 1Tb HDD is supposed to be an extra partition, but I couldn't see it in the explorer, although diskpartition was seeing it perfectly. In the end I called my friend again and we found a solution (he was supposed to have unlocked me everything but as I was on a rush at the beginning he forgot a few last things).
So, problem solved, thanks to Magic partitioner.
Anyway, thank you very much for taking the time to read that very messy help message of mine