GNU, Knoppix

[arjaybe]

Assuming your Windows is an NT derivative, like XP, you can modify your
NT bootloader to include Ubuntu.  This involves editing a file called
boot.ini.  You can google for information on the Windows bootloader or
get help on your Windows forums.



>From your description I would predict that re-installing GRUB would
again wipe out the Home Cinema thing.



good luck.


-- 
arjaybe