It had solved , the error encounters from thousands of a bad sectors :( i do not know how it happened but recovery system has repaired after then 
mount /dev/sda /mnt ext3
 grub-install /dev/sda

has worked thanks 

2010/4/24 Wahyu Darmawan <wahyu.darmawan@gmail.com>
Hi,
Have you try this :
root@rescuecd64 ~ #  grub-install /dev/sda (or some device that
installed CentOS)



2010/4/24 cahit Eyigünlü <cahit.eyigunlu@gmail.com>:
> I had a geub loader error  2 on starting centos
> and i am able to connect rescue system
> this is the result how could i get system work
> root@rescuecd64 ~ # grub
> Probing devices to guess BIOS drives. This may take a long time.
> Unknown partition table signature
>
>     GNU GRUB  version 0.97  (640K lower / 3072K upper memory)
>        [ Minimal BASH-like line editing is supported.   For
>          the   first   word,  TAB  lists  possible  command
>          completions.  Anywhere else TAB lists the possible
>          completions of a device/filename. ]
> grub>  find /boot/grub/stage1
>  find /boot/grub/stage1
> Error 15: File not found
> grub>
>
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