I finally succeed in running the ubuntu installer. Now have I switched to live-CD because I have one issue.
When I select "Install alongside windows 7", only my external drive appears. It tells me also that one more partition is hidden and I could select it by advanced formating tools.
When I click on it, my internal hard-drive does appear in the list of that tool.
I have more partitions on my external drive and internal drive. And I can easy reconise which one is internal and which one is external. But I have trouble finding out which internal partition is using windows, and which partition is just empty.
My internal disk contains 4 partitions, 2 are easy to locate because of the small sizes, but the other 2 are very confusing.
For example one disk, lets call it disk C, has 299GB storage with 99 GB used.
And my other disk, lets call it disk H, has 149GB storage with 0GB used.
When I look in the partition tool of the installer, I see these 2 disks:
322GB storage and 3GB used
179GB storage and 12,5 GB used
I prefer an installation on an internal drive...
So that gives me 3 questions:
-Is the 179GB storage one really my H drive? Or could it also be the wrong disk, since the size data is already wrong.
-Is it possible to install Ubuntu on a same disk, but another partition as windows, since the disk is not showing up in the manual "Install alongside window 7" option?
-Will it install my Ubuntu alongside windows 7 if I use the partition tool to select my internal hard-drive? Since I cannot select it with the option "Install alongside windows 7".