Download GAG from here,
It is a great little bootloader that can boot anything. After you download it you can install it to either a cd or flopy, then boot to it, choose the option 1 for language and keyboard, and find the entries for your nix and windows os and add them then add an icon for each and choose the save to harddisc option. You can also save your configured bootloader to flopy in case GAG is ever overwriten, also note when reinstalling linux to put grub or lilo on the partition linux is on with a 1 or 2 second delay to boot the kernel so you can access failsafe if need be. Or if you wish only to get windows back use gag or your windows cd to boot windows and go start run cmd , then fdisk and then repair mbr It might also be that windows is ovwrwritten and gone. Sorry if that is so.