sidney1st

Usually HP do not deliver any DVD with their laptops, then in case of problems the system can be restored in its original state by pressing F11 when you switch on the laptop. The HP partition contains everything which is necessary to perform this.
The problem, if i understand, is that your bro installed ultimate on your computer and we have to know what he did exactly.
In some cases, replacing the OS by another on this kind of laptop may destroy the HP partition, therefore it would not be possible to use the HP restore system, especially if you had XP on it originally (it is an example).
Do you know if the laptop was delivered with ultimate X64 on it ?

EDIT:
BTW, if your father has an ultimate DVD, try to repare as explained in my first post.