Interesting. Whatever works for you, I guess.

I have had good luck with extifs, and for that matter I have torn up filesystems writing with explore2fs.

so what to do now???
really I m in great confusion as y my linux is not working...

Have you tried to boot the system up manually?

If you do then the corruption in the MBR will not matter because you don't use it. Secondly in booting manually you can input one line at a time and Grub can tell you which step it cannot execute.

You can also ask Grub to display the partitions by "geometry (hd0)" etc to see everything matches with that reported in Linux.

If there is a corruption in the partition table Grub will tell you too.

Error 17 is "cannot mount selected partition" so it pays to ask how Grub sees your partitions.

It is not unusual to retrore a boot loader from time to time and everything may work fine afterward. Equally one should be aware if the hard disk is showing signs of repeated failures that can be an indication of the disk is on its way out.

sorry for late reply.....
what i did was that i tried to install grub in pen drive by the method described by saikee:
ubuntu@ubuntu:~$ mkdir /mnt/sda8
mkdir: cannot create directory `/mnt/sda8': Permission denied
ubuntu@ubuntu:~$ sudo mkdir /mnt/sda8
ubuntu@ubuntu:~$ sudo mount /dev/sda8 /mnt/sda8
mount: special device /dev/sda8 does not exist

now what should i do now??????
nothing seems to be working now

type fdisk -l to make sure that your selecting the right device

I am sure...u can see post no 6...

nobody here to help me??

try sudo mount -t <filesystemtype> /dev/sda8 <mountpoint>