For the sake of two new posts, I split my posts.
So today, I have managed to fix my lappie - still has no name huhuhu - and recovered tons of space for my hard drive. TT_TT From an alarming free space of 325 Mb of 148 Gb, now it's:
I deleted my games, unused programs, random documents, installers and reinstalled iTunes (I recovered 48 Gb worth of free space from this). iTunes takes up a lot of space and since I am not gifted with a laptop of 320 Gb, space matters. I still think I need to remove some files yet. And it's a huge relief for me. See my desktop: