how to reformat an acer laptop when you dont have ur recovery cd

actually i have two os right now but the other one was deleted manually and i wanted to remove it especially during booting sequence where i have to choose between the os, it add more problem when my old os was affected hence there are error messages that appears during the startup of win xp(my two os were winxp(pro))i cant run windows media player,what's in my mind right now is to reformat my laptop the problem is i dont have any cd's mainly the recovery cd since it was bought by the brother.,thanks u on this regard