Triple boot - uninstall restore mbr ?


I have a vista machine, added xp 2nd and ubuntu 3rd, currently boot into grub to ubuntu first with option of vista or xp next. i need to uninstall then reinstall ubuntu, so if I use easybcd to reinstall vista bootloader then remove ubuntu, will i be back to the option of booting to vista and xp like before ubuntu or will i lose xp since it was installed after vista? i don't have a vista disk and i do have an xp disk. What are my options?