You must learn Patience, padiwan!
A "kernel panic" occurs anytime something happens in the kernel that ought not to happen. In this case, the error is "spin_is_locked_on uninitialized spinlock"
and the location of the error within the kernel code is hexadecimal "dfa151a8." You can look up this address in "/boot/System.map" but the message is also telling you that the source-module giving the panic is (probably) "fs/buffer.c"
This is a very peculiar (and serious) error-case which, if it were "normal," undoubtedly would not have escaped testing. Which makes me wonder... is this just a "goofy case?"
When you say that you tried to
install Fedora Core 4 last week, did
you? Was the installation unsuccessful?
When you attempt to boot from the CD, are
you in fact booting from the CD?
What if the system is actually trying to start up from the hard-drive and is blundering into the detrius of an incomplete installation?
For your information: a "spinlock" is something that a multiprocessor-capable kernel would use to prevent several CPUs from trying to do something at the very same time. The problem being called-out is that the spinlock variable is uninitialized; something that should never be the case. The message is far more likely to be merely the last symptom
of "something that went dreadfully wrong" than to be an indication of its true cause. And the situation is far more likely to be "goofy" than "real."