simple steps to recover grub.
boot into the live cd and open a terminal windows. now type:
"sudo grub"
it'll then give you a grub prompt, "grub>"
now type: "find /boot/grub/stage1" at the grub prompt.
it'll give a output like this (hd0,7) 7 is here the example boot partition. note this down.
now type:"root (hd0,7)" (replace hd0,7 wid whatever output u'd got in the prev. step.
then type: "setup (hd0)"
it'll setup grub again.
now type:"quit"
its over! you get the grub menu now

if at all the windows entry is not there. boot into linux after performing the above mentioned steps and add this line in /boot/grub/menu.lst:
title Microsoft Windows
root (hd0,0)
savedefault
makeactive
chainloader +1
hd0,0 above assumes that you've installed windows in the first partition of the first hard disk. if this is not the case then replace 0,0 wid relevant data to ur system.