Problem in bootloader

i m using P3 system with dual boot. I have RHEL5 and Windows XP installed. 

Grub shows both the option for Windows and linux. But when i select windows to boot it shows the following ERROR : 

Missing operating System. 
I think grub has overwritten the MBR entry for XP. How to sort out this problem

Is it possible to solve this by trying 

1. booting with XP cd 
2. command line 
3. FIXMBR or FIXBOOT

Let us see the output of the follwing command 

fdisk -l 

boot with "Linux" and try to mount windows partition, 

if you can mount windows partition, then windows is OK but sector zero of 
windows partition is damaged. 
try to check "active partition" by "fdisk" command 

Did u delete any partition using disk management from windows xp.or created any new drive .that cause problem for the boot loader.if so open your system using 1st cd of linux and use rescue mode edit the grub file where you can see hd0 or sd0;5 or something like that that is the serial number of your hard that says that which drive contain the 2nd stage of boot loader.if u can identify the the linux partition using fdisk -l set just 1 number before number in grub in both /etc/grub.conf and /boot/grub/grub.conf file if u have deleted only 1 partition with windows

Posted in: Linux,Linux Real time issues.,Problem in bootloader