I'm a new user of linux.
I don't know the o.s.

I have installed a x86_64 fedora v.11 with KDE desktop on a desktop intel based PC

At the end of installation and after the last system reboot, I've completed the wizard that help the creation of a new user in KDE.

The problem is that after the insertion of user and password, the system always come back to the login window.

I tried all the options for the login.
the only one of them that works is the type failsafe.

I've redone all these tests using the root user: no difference

I do not know the system commands and then I do not know what I can do with the console to fix this problem.

May be KDE is failing to start.

Try:
press [ctrl+alt+F2]

This should take you to a CUI prompt
enter your username and password and see if you can login.(Not the root usename)

If yes there is a problem with KDE, try using GNOME (its comes with your Fedora 11 distro).
GNOME is definitely more stable than KDE.

To return to GUI use
[ctrl+alt+F1] or [ctrl+alt+F7]

To switch to GNOME (if you have installed it), look for the Session option in the Login screen.

Pls note: In Fedora 11 GUI login of root is disabled. So you cant login using KDE(Or GNOME) if you are using root as username.

If you still can't login you may have double miss typed the password. I did that onces. If it only took you like 15min to install just do a reinstall. It can be easier as long as you still have a fresh install.

Did you make sure your md5sum was correct when you downloaded it. You could have a flaw in a scripted.

Thanks for your reply.
With [ctrl+alt+F2] i can login in text mode. No other ways to log
I'm re-installing fedora 11 with gnome.

Ok. Let us know if it worked.
Can you give the config of your computer Model No. CPU, Memory, Motherboard, Graphics Hardware, if it is assembled?