Why I can't boot into Windows XP with Grub

[jqdkf@zju.edu.cn]

Hi,

Windows XP is on /dev/hda1, Linux is on /dev/hda7. I first installed
grub on /dev/hda, but it can't load XP, so I try to use lilo. But the
problem is that grub isn't removed by lilo after I installed lilo. 
Now I only can get into Linux. What should I do?

Zeng Nan