First of all, thank you for your answer.
Here is the link :Unable to start a new installation of Plone 5.1.4 on Windows [RESOLVED]
The problem N2 was solved when I suggested to use "insatnce fg" to launch the server.
On the other hand, the problem No1 remains.
Indeed it is impossible to choose its installation directory of Plone 5 under Windows.
To install Plone 5 on Windows, you must leave the default directory for installation.
Anyone have an idea about it?