其实解决办法很简单：
一、在开机的时候按一下Enter键，就出来了。因为他是被隐藏了；
二、改配置文件：/etc/grub.conf
找到这行hiddenmenu ，在这行前面加#号，或者把这行删除；
我改过后的/etc/grub.conf文件；
引用:# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You do not have a /boot partition. This means that
# all kernel and initrd paths are relative to /, eg.
# root (hd0,4)
# kernel /boot/vmlinuz-version ro root=/dev/hda5
# initrd /boot/initrd-version.img
#boot=/dev/hda
default=0
timeout=5
#splashimage=(hd0,4)/boot/grub/splash.xpm.gz
#hiddenmenu
title Fedora Core (2.6.11-1.1369_FC4)
root (hd0,4)
kernel /boot/vmlinuz-2.6.11-1.1369_FC4 ro root=LABEL=/ rhgb quiet
initrd /boot/initrd-2.6.11-1.1369_FC4.img
title WinXp
rootnoverify (hd0,0)
chainloader +1