instale ubuntu,mi parienta no puede utilizar xp

[surfero1080]

HE PORVADO ESTO PERO TAMPOCO, JODERRRRRRRRRRRRRRRRR

xavi1080surfero@ubuntu:~ $ /boot/grub/menu.lst
bash: /boot/grub/menu.lst: Permiso denegado
xavi1080surfero@ubuntu:~ $ sudo
usage: sudo -V | -h | -L | -l | -v | -k | -K | [-H] [-P] [-S] [-b] [-p prompt]
[-u username/#uid] -s | <command>
xavi1080surfero@ubuntu:~ $ /boot/grub/menu.lst
bash: /boot/grub/menu.lst: Permiso denegado
xavi1080surfero@ubuntu:~ $ su
Password:
su: Authentication failure
Disculpe.
xavi1080surfero@ubuntu:~ $