Ger van Dijck writes:
Then the next question is when having a 64 bit capable machine how I
can
install instead Fedora26 32 bit a 64 bit version of Fedora26 ?
The same way you would install Fedora 26 on any other 64 bit machine.
This is basically a fresh new install. If you have any files you want to
keep, copy them to a thumb drive, or somewhere else. Then, download Fedora
64bit, then start it. You'll have to tell the installer to remove all
existing partitions, and create new ones.