First please excuse my english, its not my native language, I am from France.
I decided recently to jump to Ubuntu. So I created a Live USB of Ubuntu, and when I want to install it on my second hard drive which has 3To capacity, the installation program doesn't recognize the free space available on it. It does show them, but doesn't allow me to reduce the free space allocated to Windows to create a new partition for Ubuntu (I'd like to get 100go). Here is a screenshot of the situation : https://img4.hostingpics.net/pics/617661Capturedu20171027224606.png
Sorry the screenshots are in French aswell. I think its still readable, but if you want me to I can make them in English. (/dev/sda is a 250go SSD for Windows)
I tried to create partitions with GParted, the problem is the same. I think it doesn't recognize the file system which is NTFS. I ran disk check in both Windows and Linux, with no errors. I tried by creating a partition from Windows (ext4) successfully, but then Ubuntu doesn't see it at all, showing me the exact same screen.
To clear the situation, here is a Windows picture of my drives : https://img4.hostingpics.net/pics/276947852.jpg I attempt to install Ubuntu on the 195Go unallocated space, but it is unseen.
I ran gdisk -l, maybe you'll see whats the problem on it because I don't. Here are the screens : https://img4.hostingpics.net/pics/793142Capturedu20171028200154.png https://img4.hostingpics.net/pics/546075Capturedu20171028200202.png
Thanks for your help.