When I installed Fedora Core 3, I set SELinux to OFF being inside a network. But, then I moved to a different provider which fully conected me to the outside world. So, I thought I would give SELinux a try. I turned SELinux on and then set is to *strict* (I think that was what made the problem.). When I rebooted, the kernal said something about relabling files. This took it a moment, but when it was done, everything booted fine. However, when I tryed to login (usihng graphical greeter with X windows) An error window said it cound not "open {use} PID..." Same thing with a no x login. Even root. I rebooted and the same message appered almost right under INIT VER.... I booted single user and turned SELinux off. What is the problem?

To be honest, SELinux is still in developement. The strict mode is *really* strict and requires you to manually fine tune the security policy in order to get a reasonably functioning system. In Fedora Core 3 the default install of SELinux uses the "targeted" rather than "strict" policy. I would highly recommend using that unless you understand SELinux and feel comfortable writing your own policies, roles, domains, etc.