Respective sir,
I am new user of RHEL5 since last two weeks I face problems in my RHEL5.I describe these problem asfollow.

1)When I start my machine that time I got message on black screen that (Hardware monitor found error. please go in power setup menu.)and (last time your system hung for improper cpu speed please adjust it)

2)To solve this problem I have change hardware monitor option in bios and also I have increase my cpu speed manually.above problem get solved but after that when I restart my machine.
I have got same problem .

3)above two problems are related with hardware but
when I solve above problem and after that when I start RHEL5 in single mode and I had type fsck on command prompt.
I dont know what happened after that. But I got error of kernel panic.
this error was resolved automically after that day my system was not get start in single mode as well as in graphical mode.

4) to solve my RHEL5 problem I try by rescue mode.
but when I enter in setup i got message that their is no RHEL5 on this drive.when I try fresh installation all partitions are shown.but at this stage I have not install fresh RHEL5.

5) To solve this problem no:4, I install RHEL5 in another Hard disk and I type fdisk -l command on terminal of new RHEL5. I got description of both of my disks.I have two VFAT(fat) partitions, one boot,one root, one swap and one extended partition on my old hard disk.
so I use mount command to mount old RHEL5 containts but only two VFAT and boot partitions get mounted .
when I try to mount my root and other partitions I got message that (Unknown fs or bad superblock,try dmesg,so|tail)

6) to solve problem of superblock I use
(fsck -b /dev/hdc2) this command but I got message that cant recover super block. no ext3 is on this drive.

7) please help me to get out of this problem because I have very Important data on my root directory.

8) I dont want to format this RHEL5 I want to solve this problem without formating RHEL5.

Respective sir please send me answers of this questions in details.

i.e why this problem come and what to do to solve it.

do one thing try unmount your " / " and remount it again.....on rescue mode ofcourse..

restart and see that solves or not..

I have try as you told but still I have same problem

respective sir i have try as you told but even i have same problen

Which is it? Is the problem solved as you said, or does it still occur? If it's a BIOS problem, then go back into your BIOS, make the changes, and SAVE them.
Again, which is it?? You say the problems above were solved..then say they weren't. And if you don't know what happened, how do you think we can help you? And if the error was resolved automatically, why are you posting?
Rescue mode takes you to a command prompt. You have to manually mount your hard drive or run commands on it. The fact that your partitions are shown, indicates they're still there.
See answer to question 4.
Again, you can't fsck a drive that's mounted. Put the single disk back into a machine, boot from CD/DVD, go into rescue mode, and fsck it from there.
If this data is important, why don't you have backups of it? And, since you're using RedHat enterprise, have you called RedHat support?? You are paying for RHEL, right?? They can assist you with this.
No idea why you had the problem, since you don't provide those details. Did you just power off your machine? Shut it down uncleanly? Were you playing with any disk/partition commands?? How old is the disk? What KIND of disk/controller?

And don't post follow-ups after five minutes. We volunteer our time here. You need to boot off of a CD/DVD..you SHOULD NOT fsck a hard drive when it's mounted, and you can't unmount the / partition when you're booted.

yeah TB0ne is very right ...

u should provide some more details regarding your problem..

all of one remounting your filesystem should solve this ..if it doesnt..there should be more details needed...to get into the root of the issue...

try

in rescue mode after unmounting your filesystem...

fsck doesnt work when your drives are mounted..