Então é assim, utilizando o código que o "hellaxe" me indicou, ao escolher o xp do grub aparece algo como "starting... ou loading up....", algo do genero, mas nao sai dali, ficou assim uns tempos e eu desliguei. Usando o código do "tangram" deu o erro como dava antes. Como me aconselharam aqui está o menu.lst:
### BEGIN AUTOMAGIC KERNELS LIST
## lines between the AUTOMAGIC KERNELS LIST markers will be modified
## by the debian update-grub script except for the default options below
## DO NOT UNCOMMENT THEM, Just edit them to your needs
## ## Start Default Options ##
## default kernel options
## default kernel options for automagic boot options
## If you want special options for specific kernels use kopt_x_y_z
## where x.y.z is kernel version. Minor versions can be omitted.
## e.g. kopt=root=/dev/hda1 ro
## kopt_2_6_8=root=/dev/hdc1 ro
## kopt_2_6_8_2_686=root=/dev/hdc2 ro
# kopt=root=UUID=ade07f3e-7830-422b-b765-787b2759f2e2 ro
## Setup crashdump menu entries
## e.g. crashdump=1
# crashdump=0
## default grub root device
## e.g. groot=(hd0,0)
# groot=(hd0,6)
## should update-grub create alternative automagic boot options
## e.g. alternative=true
## alternative=false
# alternative=true
## should update-grub lock alternative automagic boot options
## e.g. lockalternative=true
## lockalternative=false
# lockalternative=false
## additional options to use with the default boot option, but not with the
## alternatives
## e.g. defoptions=vga=791 resume=/dev/hda5
# defoptions=quiet splash
## should update-grub lock old automagic boot options
## e.g. lockold=false
## lockold=true
# lockold=false
## Xen hypervisor options to use with the default Xen boot option
# xenhopt=
## Xen Linux kernel options to use with the default Xen boot option
# xenkopt=console=tty0
## altoption boot targets option
## multiple altoptions lines are allowed
## e.g. altoptions=(extra menu suffix) extra boot options
## altoptions=(recovery) single
# altoptions=(recovery mode) single
## controls how many kernels should be put into the menu.lst
## only counts the first occurence of a kernel, not the
## alternative kernel options
## e.g. howmany=all
## howmany=7
# howmany=all
## should update-grub create memtest86 boot option
## e.g. memtest86=true
## memtest86=false
# memtest86=true
## should update-grub adjust the value of the default booted system
## can be true or false
# updatedefaultentry=false
## ## End Default Options ##
title Ubuntu, kernel 2.6.20-16-generic
root (hd0,6)
kernel /boot/vmlinuz-2.6.20-16-generic root=UUID=ade07f3e-7830-422b-b765-787b2759f2e2 ro quiet splash
initrd /boot/initrd.img-2.6.20-16-generic
quiet
savedefault
title Ubuntu, kernel 2.6.20-16-generic (recovery mode)
root (hd0,6)
kernel /boot/vmlinuz-2.6.20-16-generic root=UUID=ade07f3e-7830-422b-b765-787b2759f2e2 ro single
initrd /boot/initrd.img-2.6.20-16-generic
title Ubuntu, kernel 2.6.20-15-generic
root (hd0,6)
kernel /boot/vmlinuz-2.6.20-15-generic root=UUID=ade07f3e-7830-422b-b765-787b2759f2e2 ro quiet splash
initrd /boot/initrd.img-2.6.20-15-generic
quiet
savedefault
title Ubuntu, kernel 2.6.20-15-generic (recovery mode)
root (hd0,6)
kernel /boot/vmlinuz-2.6.20-15-generic root=UUID=ade07f3e-7830-422b-b765-787b2759f2e2 ro single
initrd /boot/initrd.img-2.6.20-15-generic
title Ubuntu, memtest86+
root (hd0,6)
kernel /boot/memtest86+.bin
quiet
title windows
root (hd0,4)
makeactive
chainloader +1
### END DEBIAN AUTOMAGIC KERNELS LIST
Espero que me possam ajudar.