Hi to everyone
I prepared a system with Centos 5.1 with one LVM and two NICs for general purpose experiments in Linux (as a ). System run smoothly for several weeks and i could discover the strength of Linux day by day. Last week i decided to investigate the bridging procedure in order to bridge two networks that i had. I made yum install for all the required , i configure the bridge using brctl and everything worked fine. The problem begun when i decided to delete the bridge and roll back to the previous situation (two unbridged NICs). After bridge deletion, i made a reboot and from then the system responds "Error 15 : File not found". I understand that it cannot find the kernel and this is the strange thing. I search the disk and i couldn't find the kernel and the .img file in the /boot directory (or somewhere else). My current grub conf is

# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You have a /boot partition. This means that
# all kernel and initrd paths are relative to /boot/, eg.
# root (hd0,1)
# kernel /vmlinuz-version ro root=/dev/VolGroup00/LogVol00
# initrd /initrd-version.img
#boot=/dev/sda
default=2
timeout=5
splashimage=(hd0,1)/grub/splash.xpm.gz
hiddenmenu
title Fedora (2.6.27.25-78.2.56.fc9.i686)
root (hd0,1)
kernel /vmlinuz-2.6.27.25-78.2.56.fc9.i686 ro root=/dev/VolGroup00/LogVol00 rhgb quiet
initrd /initrd-2.6.27.25-78.2.56.fc9.i686.img

SO, my question is: Is there any way to restore the kernel files (even the original - i have the installation CDs) in order to have the system back to operation or is there any way to perform a re-installation without losing any data?

thanks

The sample of your grub.conf lists only one operating system (Fedora). CentOS is not listed. Also, your grub.conf defaults to the third item in the list of OSs, but only one OS is listed.
The default=2 is grub-speak for the third item in the menu list (numbering starts at 0).

Did you omit part of your grub.conf? if not, change the default to 0, then reboot to see if Fedora boots normally.

You are absolutely right! I paste something wrong.
When i boot and grub loads i use e and i saw the following commands in grub:

root (hd0,0)
kernel /xen.gz-2.6.18-8.1.8.el5
module /vmlinuz-2.6.18-8.1.8.el5xen ro root=/dev/VolGroup00/LogVol00 rhgb quiet
module /initrd-2.6.18-8.1.8.el5xen.img