Location of various system configuration related files :part-1

We know that Linux Operating systems are totally distributed as a open source codes operating system.Here if we know about all the commands and variable definitions then we are very much able to change the configuration files as needed for our different purposes.Here the locations of different configuration related files are given below.In my next post i will discuss about how can we modify all the commands.

"LINUX RESCUE"

Suppose you have two Operating systems "Windows & Linux" in parallel.Somehow if windows becomes corrupted.Then what should you do?Reinstalling the previous OSs again is not the solution.Here is a solution.
If windows becomes corrupted then you should recover your previous grub-Boot-Loader.If you can recover it then you will be able to rescue your Existing Linux OS.

First you have to insert your Linux-Bootable disk.
And there type [linux rescue]
then there will appear some messages.
then type [/mnt/sysimage]
then [chroot/mnt/sysimage]
then [grub-install /dev/hda]

Thus this will install newly Grub-boot-loader to MBR(Master Boot Record)
Then type [reboot]
After a successful rebooting a boot-loader will be appeared.Then select the first Linux OS.And press'e' button.Here 'e' for editing.
then type exactly the following codes (without third bracket).
[ root (hd0,7)
kernel /vmlinuz-2.6.18-8.el5 ro root=LABEL=/ rhgb quiet crashkernel=128M@16M
initrd /initrd-2.6.18-8.el5.img ]
then press 'b' button to boot your selected Linux OS.