How to remove ubuntu 9.10

Hello,
i am subramani from dindigul. i'am new in ubuntu. i installed the ubuntu os on my labtop.
but i couldnot delete that os.
now fullen fully linux have my labtop.
when i am insert my xp cd on booting section, xp does not work. if i insert linux cd,it will be work.

i don't know how to uninstall ubuntu os on my labtop.
ple help me.
cell no: 9791361780